Guidelines for Adult Immunisation

Upcoming Vaccines​

COVID-19

Updated in November 2023

Introduction

The COVID 19 pandemic has affected about 230 countries and territories around the world. One year after the pandemic was declared in March 2020, there were more than 130 million cases and more than 2.8 million deaths worldwide. As of mid-2023, there are more than 690 million confirmed cases, and more than 6.8 million deaths worldwide. Malaysia reported a total of more than 5 million confirmed cases and more than 37,000 deaths as of mid-2023. 

Since the emergence of the COVID-19 pandemic, vaccines have been at the forefront of global efforts to curb the spread of the virus. Tremendous progress has been made in developing, testing, and distributing vaccines against COVID-19. Nearly all countries have implemented COVID-19 vaccines and more than 13 billion doses have been administered globally as of December 2022 in this massive and unprecedented vaccine deployment, with an estimated 19.8 million deaths averted in 2021. 

WHO recommends that countries should continue to work towards vaccinating at least 70% of their populations, prioritizing the vaccination of 100% of health workers and 100% of the most vulnerable groups, including people who are over 60 years of age and those who are immunocompromised or have underlying health conditions.

 

Vaccines

 

The latest status of vaccines indicates remarkable progress in combating the pandemic. Vaccines have proven highly effective in reducing severe illness, hospitalizations, and deaths. Although new variants present challenges, ongoing research and modifications strive to maintain vaccine efficacy. Global distribution efforts continue to evolve, with an emphasis on equitable access for all. Vaccination campaigns have been crucial in slowing the transmission of COVID-19 and mitigating its impact. Various global initiatives, such as COVAX, have facilitated access to vaccines for low- and middle-income countries, aiming to close the vaccination gap and reach marginalized populations.

The different types of COVID-19 vaccines are as below:

mRNA Vaccines (Pfizer-BioNTech and Moderna) 

  • Mechanism: mRNA vaccines deliver genetic material (messenger RNA) that provides instructions for cells to produce the SARS-CoV-2 spike protein. This triggers an immune response, producing antibodies against the virus.
  • Efficacy: Both Pfizer-BioNTech and Moderna vaccines have shown high efficacy rates of over 90% in preventing symptomatic infection in clinical trials.
  • Dosage: These vaccines require two doses administered a few weeks apart (Pfizer-BioNTech: 21 days, Moderna: 28 days).
  • Storage: Pfizer-BioNTech vaccine requires ultra-cold storage (-70 to -80°C), while Moderna can be stored at regular freezer temperatures (-20°C).
 

Viral Vector Vaccines (AstraZeneca, Johnson & Johnson, and CanSino)

  • Mechanism: Viral vector vaccines use a modified harmless virus to deliver a gene that encodes the spike protein into cells. The spike protein production triggers an immune response.
  • Efficacy: AstraZeneca, Johnson & Johnson, and CanSino vaccines have demonstrated efficacy rates ranging from 60% to over 90% in preventing severe illness, hospitalizations, and deaths.
  • Dosage: AstraZeneca usually requires two doses, while Johnson & Johnson and CanSino are single-dose vaccines. 
  • Storage: AstraZeneca and CanSino vaccines can be stored at regular refrigerator temperatures, while Johnson & Johnson has more flexible storage requirements.

Protein Subunit Vaccines (Novavax)

  • Mechanism: Protein subunit vaccines contain the SARS-CoV-2 spike protein. They stimulate an immune response, prompting the production of antibodies. 
  • Efficacy: Novavax vaccine has shown high efficacy rates of over 90% against symptomatic infection and variants in clinical trials.  Dosage: Novavax requires two doses administered a few weeks apart.
  • Storage: The Novavax vaccine can be stored at regular refrigerator temperatures.

Inactivated Vaccines (Sinovac, Bharat Biotech)

  • Mechanism: Inactivated vaccines use SARS-CoV-2 that has been inactivated to trigger an immune response.
  • Efficacy: Sinovac and Bharat Biotech vaccines have shown variable efficacy rates in preventing symptomatic infection, ranging from 50% to over 80%
  • Dosage: Sinovac and Bharat Biotech vaccines typically require two doses administered a few weeks apart.
  • Storage: These vaccines can be stored at regular refrigerator temperatures.

*Note that these are general characteristics, and each vaccine may have specific variations in dosage, efficacy, and storage requirements.

 

Malaysia has procured COVID-19 vaccines from various manufacturers, including Pfizer-BioNTech, AstraZeneca, Sinovac, and CanSino. The government has engaged in bilateral agreements, participation in the COVAX facility, and direct purchases to ensure a sufficient vaccine supply. A phased vaccination approach has been implemented to prioritize high-risk groups and front-line workers, the elderly, individuals with comorbidities, essential workers, followed by the general population. The MySejahtera mobile application and website was established as the primary platform for COVID-19 vaccine registration and digital records.

 

Vaccination centres, including public and private healthcare facilities, stadiums, convention centres, and community halls, were set up nationwide. These centres were utilized in administering the vaccines and ensuring the progress of the vaccination campaign. Public outreach and education campaigns were conducted to promote vaccination, address vaccine hesitancy and provide accurate information to the public through various channels, including social media, press conferences and community engagement.

 

Following the transition to endemicity of COVID-19, MySejahtera app is now utilised for healthcare information, infectious diseases tracking, health screening and appointments.

 

Challenges persist in achieving widespread vaccination coverage including vaccine hesitancy, misinformation and logistical hurdles. Collaborative efforts among countries, pharmaceutical companies and health organizations are required for research, development, and distribution of vaccines. Maintaining global manufacturing capacities and ensuring the availability of vaccines for future variants will be vital in mitigating the impact of potential outbreaks.  

 

Further information on the progress of the vaccine pipeline can be obtained at the WHO “COVID-19 vaccine tracker and landscape”. This platform compiles detailed information of each COVID-19 vaccine candidate in development, and closely monitor their progress through the pipeline. As of the first quarter of 2023, a total of 183 vaccines are under clinical development and 199 candidates are in pre-clinical development. The COVID-19 vaccine tracker platform:

  • Provides summary tables of COVID-19 vaccine candidates in both clinical and pre-clinical development
  • Provides analysis and visualization for vaccine candidate categories
  • Tracks the progress of each vaccine from pre-clinical, Phase 1, Phase 2 through to Phase 3 efficacy studies and including Phase 4 registered as interventional studies
  • Provides links to published reports on safety, immunogenicity and efficacy data
  • Includes information on key attributes of each vaccine candidate
  • Enables search for COVID-19 vaccines through various criteria such as vaccine platform, schedule of vaccination, route of administration, developer, trial phase and clinical endpoints.

Vaccines available in Malaysia

 

COVID-19 vaccines that have been approved for use in Malaysia include Pfizer-BioNTech, AstraZeneca, Sinovac and Cansino. 

Products that are registered with NPRA are listed below:

  1. COMIRNATY Concentrate for Dispersion for Injection. Pfizer (Malaysia) Sdn Bhd.
  2. COMIRNATY 10mcg Concentrate for Dispersion for Injection. Pfizer (Malaysia) Sdn Bhd.
  3. COMIRNATY (Tris/Sucrose) 30 mcg Solution for Injection. Pfizer (Malaysia) Sdn Bhd.
  4. COMIRNATY Original/Omicron BA.4-5 (15/15 micrograms)/dose Dispersion for Injection. Pfizer (Malaysia) Sdn Bhd.
  5. COMIRNATY Original/Omicron BA.4-5 (5/5 micrograms)/dose Concentrate for Dispersion for Injection. Pfizer (Malaysia) Sdn Bhd.
  6. CoronaVac Suspension for Injection COVID-19 Vaccine (Vero Cell), Inactivated. Sinovac Life Sciences Co. Ltd.
  7. Convidecia (Trade Mark) Recombinant Novel Coronavirus Vaccine (Adenovirus Type 5 Vector) Solution for Injection. Cansino Biologics Inc, China.
  8. COVID-19 Vaccine AstraZeneca Solution for Injection (Vaxzevria). Astrazeneca AB, Sweden
  9. COVILO Suspension for Injection COVID-19 Vaccine (Vero Cell), Inactivated. Beijing Institute of Biological Products Co., Ltd (BIBP), China.
  10. Spikevax 0.20 mg/mL dispersion for injection COVID-19 mRNA Vaccine (nucleoside modified, Moderna). Zuellig Pharma Sdn Bhd.
  11. COVAXIN (Whole Virion, Inactivated Coronavirus (SARS-CoV-2) Vaccine) Suspension for Intramuscular Injection. Averroes Pharmaceutical Sdn Bhd.
  12. Vaxzevria Solution for Injection. ASTRAZENECA SDN. BHD.
  13. EVUSHELD 100 mg/mL Solution for Injection. Astra Zeneca Sdn Bhd.

The available vaccines are regularly updated and the list of current products can be searched at the NPRA website for product search:

https://quest3plus.bpfk.gov.my/pmo2/index.php

Modes of administration

 

Vaccines administered by intramuscular injections include Pfizer-BioNTech, AstraZeneca, Sinovac, CanSino, Johnson & Johnson, Moderna, Bharat Biotech, Novavax, Sinopharm, Sputnik V, Covovax, Covishield, Covaxin, Abdala, Soberana 02, EpiVacCorona. 

Vaccines administered by intranasal route include RBD-Dimer, Covovax, and various other candidates of intranasal vaccines.

Target groups in Malaysia

 

Vaccination strategies vary between countries based on specific circumstances and available vaccine supply. The target groups are based on national vaccination strategies and priorities. Malaysia has been actively engaged in its nationwide COVID-19 vaccination campaign and the groups that are prioritized are as below:

  • Healthcare Workers and frontliners, including doctors, nurses, paramedics, and other healthcare staff directly involved in COVID-19 patient care, are among the first to be vaccinated to protect them and maintain essential healthcare services.
  • Elderly population, typically aged 60 years and above, are prioritized due to their increased vulnerability to severe illness and higher mortality rates.
  • Individuals with underlying medical conditions, such as diabetes, heart disease, respiratory disorders, and immunocompromised conditions, are also prioritized as they have a higher risk of severe COVID-19 outcomes. 
  • Essential workers, including law enforcement personnel, teachers, public transportation workers, and those involved in food supply and distribution, are included in the priority groups to maintain critical services, and reduce community transmission.
  • High-risk and vulnerable populations: individuals living in high-risk settings such as nursing homes, long-term care facilities, and correctional institutions, as well as those in marginalized or disadvantaged communities, may receive priority for vaccination.
  • General population: once priority groups are vaccinated, move towards vaccinating the general population, starting with younger age groups and expanding eligibility based on vaccine availability and public health goals.

As of October 2023, more than 27.5 million people or 84.3% of the total population in Malaysia have received at least two doses of the vaccine.  More than 28.1 million (86.1%) have received at least 1 dose. The latest data and statistics on the National COVID-19 Immunisation Program can be accessed at the MOH website: https://data.moh.gov.my/covid-vaccination

 
The definition of “fully vaccinated”, by vaccine types and vaccine brands is subject to current MOH’s recommendations and will be updated from time to time. Malaysia’s latest COVID-19 vaccination policy and requirements to be considered as fully vaccinated currently can be referred at this website: https://mysejahtera.moh.gov.my/en/covid-19/latest-malaysia-covid-19-vaccination-policy 
 
Details on the national vaccination programme, contacts, news and updates may be obtained at the MOH website: https://covid-19.moh.gov.my/vaksin-covid-19

Contraindications and Adverse Events

 

COVID-19 vaccines are generally safe and well-tolerated. Specific contraindications and adverse events may vary depending on the vaccine brand and individual factors. Extensive vaccine safety monitoring systems have been established to assess and ensure the safety of vaccines. Adverse events associated with vaccines have been generally rare, and the benefits of vaccination have far outweighed the risks.

Contraindications

  • Allergic reaction: individuals with a known history of severe allergic reactions (anaphylaxis) to any component of a COVID-19 vaccine should not receive that particular vaccine.
  • Previous severe reaction: individuals who have had a severe adverse reaction (anaphylaxis) to a previous dose of a COVID-19 vaccine should not receive further doses of that vaccine.
  • Vaccine-specific contraindications: some vaccines may have specific contraindications based on individual characteristics, such as pregnancy or certain underlying medical conditions.
  • For detailed contraindications, it is important to refer to the specific vaccines.
Adverse Events
 
  • Mild reactions: common side effects include pain at the injection site, fatigue, headache, muscle pain, chills, fever and nausea. These are generally mild and resolve within a few days.
  • Allergic reactions: While rare, allergic reactions can occur following vaccination, ranging from mild allergic reactions such as hives, to severe allergic reactions (anaphylaxis). These reactions usually occur within a few minutes to a few hours after vaccination.
  • Thrombosis with thrombocytopenia: in rare cases, specific COVID-19 vaccines such as the AstraZeneca and Johnson & Johnson vaccines, have been associated with a rare blood clotting disorder called thrombosis with thrombocytopenia syndrome (TTS). Signs and symptoms include severe headache, abdominal pain, leg pain, or shortness of breath.
  • Myocarditis and pericarditis: in very rare instances, particularly among younger males, some COVID-19 vaccines have been associated with cases of myocarditis and pericarditis. These cases are generally mild and resolve with appropriate treatment.

Evidence of effectiveness

 

COVID-19 vaccines have demonstrated evidence of effectiveness in preventing severe illness, hospitalizations and deaths associated with the disease. COVID-19 vaccines including Pfizer-BioNTech, Moderna, AstraZeneca and Johnson & Johnson, underwent rigorous clinical trials involving tens of thousands of participants. High efficacy rates have been shown, for example Pfizer-BioNTech, Moderna, and AstraZeneca efficacy rates against symptomatic infection ranging from 70% to over 95%. 

Real-world evidence has also consistently supported the effectiveness of COVID-19 vaccines in reducing the risk of severe illness, hospitalization, and death. Vaccinated individuals have significantly lower rates of infection compared to unvaccinated individuals, with milder symptoms and a reduced risk of severe complications, even in the face of emerging variants. 

Countries that have achieved high vaccination rates have observed a decline in COVID-19 cases, hospitalizations, and deaths. Vaccination campaigns have contributed to controlling the spread of the virus, reducing the overall burden on healthcare systems, and mitigating the impact of the pandemic. The evidence collected from clinical trials, real-world data and population-level observations consistently supports the effectiveness of COVID-19 vaccines. 

Virus variants have demonstrated increased transmissibility, and in some cases, resistance to certain antibodies. As the virus continues to evolve, the emergence of new variants has prompted concerns about waning vaccine effectiveness. Studies have indicated that while some variants may have reduced vaccine effectiveness, vaccination still provides significant protection against severe disease, hospitalization, and death. The effectiveness may vary depending on the specific variants . 

The impact of virus variants on vaccine effectiveness continues to be monitored, and the potential need for booster shots and vaccine modifications to ensure long-term effectiveness. The bivalent booster of the COVID-19 vaccine was produced in 2022. It contains both the original vaccine strain and the Omicron BA.4 and BA.5 (BA.4/BA.5) variants of SARS-CoV-2. In April 2023 the FDA authorized the Bivalent Moderna COVID-19 Vaccine and the Bivalent Pfizer-BioNTech COVID-19 Vaccine. The monovalent versions are no longer authorized for use in the US. Furthermore, as the virus drifted from its origins, data also shows the bivalent vaccine may have lost effectiveness against the current (XBB) variants. Future vaccines may need to be reconfigured to target XBB variants and other emerging variants. 

The field of COVID-19 vaccine trials is dynamic, and new findings and updates can emerge rapidly. It is essential to consult reputable sources, such as peer-reviewed publications, clinical trial registries, and official statements from regulatory authorities and health organizations. The following are some of the sources:

  • World Health Organization (WHO): regular updates on vaccine trials, including information on global vaccine research initiatives, clinical trial progress and emerging findings.
  • Official statements and publications from national health organizations and regulatory authorities such as the U.S. Food and Drug Administration (FDA), European Medicines Agency (EMA), National Pharmaceutical Regulatory Agency (NPRA, Malaysia).
  • Peer-reviewed medical journals such as The New England Journal of Medicine, The Lancet, and Journal of the American Medical Association (JAMA) regularly feature research articles and important findings related to vaccine trials.
  • ClinicalTrials.gov: this comprehensive database provides information on ongoing and completed clinical trials, including COVID-19 vaccine trials. Healthcare professionals can search for specific trials, access study protocols, and review trial updates.
  • Professional organizations such as the American Medical Association (AMA) and the Infectious Diseases Society of America (IDSA), provide updates and guidance on COVID-19 vaccines.

References

  1. CDC (2023). Interim Clinical Considerations for Use of COVID-19 Vaccines in the United States. Available at https://www.cdc.gov/vaccines/covid-19/clinical-considerations/interim-considerations-us.html#covid-vaccines
  2. CDC (2023). COVID-19 Vaccine Interim COVID-19 Immunization Schedule for Persons 6 Months of Age and Older. Available at https://www.cdc.gov/vaccines/covid-19/downloads/COVID-19-immunization-schedule-ages-6months-older.pdf
  3. The Ministry of Health Malaysia. The latest data on the pandemic in Malaysia. Available at https://data.moh.gov.my/covid
  4. Ministry of Health, Malaysia (2023). Vaccinations in Malaysia. Available at https://data.moh.gov.my/covid-vaccination
  5. Ministry of Health, Malaysia (2022). Latest COVID-19 Vaccination Policy. Available at https://mysejahtera.moh.gov.my/en/covid-19/latest-malaysia-covid-19-vaccination-policy
  6. Ministry of Health, Malaysia (2021). MaHTAS COVID-19 Rapid Evidence Updates: COVID-19 Candidate Vaccines (Update) Based on available evidence up to 15 February 2021. Available at https://covid-19.moh.gov.my/kajian-dan-penyelidikan/mahtas-covid-19-rapid-evidence-updates/COVID-19_VACCINES_15022021.pdf
  7. National Pharmaceutical Regulatory Agency (NPRA), Malaysia. Available at https://www.npra.gov.my/index.php/en/
  8. Paul A. Offit. (2023). Bivalent Covid-19 Vaccines -A Cautionary Tale. N Engl J Med 2023; 388:481-483. DOI: 10.1056/NEJMp2215780
  9. Wang, J. (2021). A bivalent recombinant vaccine: a promising strategy against both SARS-CoV-2 variants and wild type of the virus. Sig Transduct Target Ther 6, 278. https://doi.org/10.1038/s41392-021-00691-4
  10. World Health Organisation (2022). Global COVID-19 Vaccination Strategy in a Changing World: July 2022 update. Available at https://www.who.int/publications/m/item/global-covid-19-vaccination-strategy-in-a-changing-world–july-2022-update
  11. World Health Organisation (2023). COVID-19 vaccine tracker and landscape. Available at https://www.who.int/publications/m/item/draft-landscape-of-covid-19-candidate-vaccines
  12. World Health Organisation (2023). Strategic Advisory Group of Experts on Immunization (SAGE) COVID-19 vaccines technical documents. Available at https://www.who.int/groups/strategic-advisory-group-of-experts-on-immunization/covid-19-materials