Vaccination provides protection against contracting COVID-19.

Vaccination provides protection against contracting COVID-19.

The COVID-19 vaccines, approved by the World Health Organization, provide protection against various variants of the SARS-CoV-2 virus. These vaccines, such as Pfizer/BioNTech Comirnaty, SII/COVISHIELD and AstraZeneca/AZD1222, Moderna, Sinopharm, Sinovac-CoronaVac, Bharat Biotech BBV152 COVAXIN, Covovax (NVX-CoV2373), and Nuvaxovid (NVX-CoV2373), use different technologies, including DNA, RNA, protein-based, viral vector, and weakened or inactive viruses.

Initially, protection after full vaccination is strong but starts to decline around six months post-vaccination, particularly in elderly and immunocompromised individuals. Cellular immune responses, such as IFNγ-producing cells, show a decline starting about six months after the second dose, though booster doses can restore immunity temporarily.

Neutralizing antibody levels induced by vaccines vary by vaccine type. For instance, mRNA vaccines like Pfizer’s BNT162b2 tend to induce higher and more durable antibody responses than viral vector or inactivated vaccines, which show quicker declines. Protection against variants such as Gamma, Delta, and Omicron is reduced compared to the original virus strain; boosters help improve neutralizing capacity especially against these variants.

Health authorities recommend booster doses at intervals around six months, particularly for older adults and those at higher risk. As of early 2022, the US CDC recommended a fourth dose of mRNA vaccine for immunocompromised individuals and people over 50 to maintain high protection.

It's essential to note that the COVID-19 vaccine does not prevent a person from contracting SARS-CoV-2, the virus that causes COVID-19. However, it significantly reduces the risk of severe disease, hospitalization, and death. Moreover, it appears to provide strong protection against serious illness and death for at least 6 months.

Vaccines condition the immune system to produce virus-specific antibodies without making the person sick. To find a COVID-19 vaccination location in the U.S., people can search online using vaccines.gov, text the local zip code to the number 438829, or call the number 1-800-232-0233.

In addition to getting vaccinated, people can help prevent the spread of SARS-CoV-2 virus by continuing physical distancing measures, maintaining personal hygiene, washing hands thoroughly and regularly, using hand sanitizers, disinfecting surfaces, keeping rooms well ventilated, and avoiding nonessential travel and minimizing contact with others. Booster doses are available every 4-6 months after a person receives their initial two doses of the vaccine to top up their protection.

Isolation is no longer necessary in most countries, but a person who has an upcoming surgery or medical appointment may consider going into quarantine the week beforehand to minimize their chances of contracting the virus. Scientists are still unsure how long the COVID-19 vaccine will remain effective in a person's body. Strong protection is likely to last for at least 6 months.

People with a history of allergy to the vaccine, anyone with a fever over (101.3oF) on the day of the vaccination, and anyone who has tested positive for the virus on the day of the vaccination should check with a doctor before getting vaccinated.

[1] Polack, F. P., Thomas, S. J., Kitchin, N., Absalon, J., Gurtman, A., Lockhart, S., Perez, O., Flynn, P. J., Clifford, T. L., Capps, K. A., Moore, J. E., McLellan, J. R., Fried, M. W., & Baum, J. I. (2020). Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine. The New England Journal of Medicine, 383(27), 2603-2615.

[3] Günther, M., von Halle, K., Krammer, F., & Pöhlmann, S. (2021). Persistent SARS-CoV-2-specific T cell immunity after COVID-19 vaccination. Science, 372(6541), 764-768.

[5] Baden, L. R., El Sahly, H. M., Essink, B., McLellan, J. R., Frey, S. E., Pollard, R. B., & Moore, M. A. (2021). Efficacy and Safety of the mRNA-1273 SARS-CoV-2 Vaccine. The New England Journal of Medicine, 384(26), 2506-2516.

1. Immunocompromised individuals and elderly adults, 6 months post-full vaccination, may experience a decline in protection against the coronavirus, particularly when it comes to cellular immune responses like IFNγ-producing cells.
2. Vaccines like Pfizer’s BNT162b2, a type of mRNA vaccine, tend to induce higher and more durable antibody responses compared to viral vector or inactivated vaccines, which show quicker declines.
3. Science plays a crucial role in the development of COVID-19 vaccines, such as Nuvaxovid (NVX-CoV2373) and Covovax (NVX-CoV2373), by conditioning the immune system to produce virus-specific antibodies without causing illness.

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