COVID-19 Vaccines to prevent SARS-CoV-2 infection

Coronavirus disease 2019 (COVID-19): Vaccines to prevent SARS-CoV-2 infection

 

Coronavirus disease 2019 (COVID-19): Vaccines to prevent SARS-CoV-2 infection

 

Vaccination preventing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are considered the most promising approach to manage the pandemic. Developing SARS-CoV-2 vaccine is going on at an unprecedented speed.  

Unhuman primate studies & epidemiologic human trials inform that SARS-CoV-2 infection may result in evolution of functional neutralizing AB that’re followed by protection against reinfection. These landmarks support the consideration that a vaccine that produce neutralizing AB could also prevent any subsequent infection. Neutralizing AB & Th1-polarized cellular immune response are believed to be essential in limiting the risk of vaccine-enhanced illness. Primarily, the main antigenic target for SARS-CoV-2 vaccine is the large surface spike proteins that bind to the angiotensin-converting enzyme 2 (ACE2) receptor on host cell & resulting in membrane fusion.  

 

SARS-CoV-2 vaccine is currently developed via several variable platforms. Some with traditional approach, e.g., inactivated virus or live attenuated virus platform, others with new approaches, e.g., recombinant proteins & vector vaccine, and some have never been employed in a licensed vaccination before, e.g. RNA & DNA vaccine. A variety of vaccine candidates have shown immunogenicity without major safety profiles in the early-phases human studies. 👉Two mRNA vaccine candidates have also been reported to have about 95 % vaccine efficacy in prevention of lab-confirmed symptomatizing coronavirus infection 2019 (COVID-19). Many vaccines are now available in many countries.  

 

In the US, added to the traditional process for licensing a vaccine, the FDA can make vaccines that permit specific safety & efficacy profiles available faster through an emergency use authorization (EUA). As regard vaccines allowed under EUA, physicians should explain to the potential recipients that the vaccine didn’t licensed yet, the reason(s) it is not licensed, and what are the expected information the FDA is waiting for before commencing a full-licensed vaccine; a signed informed consent document is currently NOT warranted.  

 

Deployment of the limited vaccine supplies that will be initially available should be equitable and efficient. Several expert organizations have provided guidance for vaccine allocation approaches that maximize the individual and societal benefits of vaccination. These generally prioritize workers in essential industries (including health care) and individuals at risk of severe infection. Following availability & widespread uptake of SARS-CoV-2 vaccination, efficacy profile that were not considered in clinical studies will need to be assessed, include the following: 👉

1)    Longevity of protection & possible need for more doses,

2)    Effectiveness in subpopulation (s) not considered in the study, &

3)    Potential Impact on community transmission.

Safety profile that was not initially clear may also appear. In the US, existing active & passive monitoring system are being triggered to closely evaluate safety of SARS-CoV-2 vaccine.  

 

REFERENCES

1. World Health Organization. Director-General's remarks at the media briefing on 2019-nCoV on 11 February 2020. http://www.who.int/dg/speeches/detail/who-director-general-s-remarks-at-the-media-briefing-on-2019-ncov-on-11-february-2020 (Accessed on February 12, 2020).
2. World Health Organization. Draft landscape of COVID-19 candidate vaccines. https://www.who.int/publications/m/item/draft-landscape-of-covid-19-candidate-vaccines (Accessed on October 20, 2020).
3. College of Physicians of Philadelphia. The History of Vaccines: Vaccine Development, Testing, and Regulation. https://www.historyofvaccines.org/content/articles/vaccine-development-testing-and-regulation (Accessed on October 20, 2020).
4. Corbett KS, Flynn B, Foulds KE, et al. Evaluation of the mRNA-1273 Vaccine against SARS-CoV-2 in Nonhuman Primates. N Engl J Med 2020; 383:1544.
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6. Brighton Collaboration. Accelerated Assessment of the Risk of Disease Enhancement with COVID-19 Vaccines​, March 2020. https://brightoncollaboration.us/brighton-collaboration-cepi-covid-19-web-conference/ (Accessed on October 20, 2020).
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