Some people who are fully vaccinated against COVID-19 will still get sick because no vaccine is 100% effective
WHO states that the COVID-19 vaccines produce protection against the disease, as a result of developing an immune response to the SARS-Cov-2 virus. Developing immunity through vaccination means there is a reduced risk of developing the illness and its consequences. This immunity helps you fight the virus if exposed. Vaccination protects one from getting seriously ill and dying from COVID-19. For the first fourteen days after getting a vaccination, one does not have significant levels of protection, then it increases gradually. For a single dose vaccine, immunity will generally occur two weeks after vaccination. For two-dose vaccines, both doses are needed to achieve the highest level of immunity possible.
WHO has approved a few vaccines under its Emergency Use Listing (EUL) namely Pfizer/BioNtech Comirnaty vaccine; the SII/Covishield and AstraZeneca/AZD1222 vaccines (developed by AstraZeneca/Oxford and manufactured by the Serum Institute of India and SK Bio respectively); the Janssen/Ad26.COV 2.S developed by Johnson & Johnson; the Moderna COVID-19 vaccine (mRNA 1273) and the Sinopharm COVID-19 vaccine (produced by Beijing Bio-Institute of Biological Products Co Ltd, subsidiary of China National Biotec Group).
The approved vaccines have varying degrees of efficaciousness. Pfizer has a 95% efficacy rate and Moderna’s efficacy rate is between 86-94.1% in preventing COVID-19 in those without prior infection. Johnson & Johnson has a 72% overall efficacy and 86% efficacy against severe disease in the U.S. AstraZeneca updated its data analysis of its phase 3 trials in March 2021, showing its vaccine to be 76% effective at reducing the risk of symptomatic disease 15 days or more after receiving the two doses, and 100% against severe disease. The company also said the vaccine was 85% effective in preventing COVID-19 in people over 65. WHO’s Strategic Advisory Group of Experts on Immunization (SAGE) has determined that the vaccine efficacy for symptomatic and hospitalized disease was estimated to be 79%, all age groups combined.
Since COVID vaccines have only been developed in the past months, it’s too early to know the duration of protection of COVID-19 vaccines. Further research is needed to answer this question. However, WHO reports that available data suggest that most people who recover from COVID-19 develop an immune response that provides at least some period of protection against reinfection – although we’re still learning how strong this protection is, and how long it lasts.
While a COVID-19 vaccine will protect one from serious illness and death, we still don’t know the extent to which it keeps an individual from being infected and passing the virus on to others. WHO has advised that to help keep others safe, we should continue to maintain at least a 1-metre distance from others, clean our hands frequently and wear a mask, particularly in enclosed, crowded or poorly ventilated spaces. WHO recommends that we should continue to follow guidance from local authorities based on the situation and risk where we live.
The COVID-19 pandemic has given rise to a lot of potentially dangerous misinformation. For reliable advice on COVID-19 including symptoms, prevention and available treatment, please refer to the World Health Organisation or your national healthcare authority.
The COVID-19 pandemic has given rise to a lot of potentially dangerous misinformation. For reliable advice on COVID-19, including symptoms, prevention, and available treatment, please refer to the World Health Organization or your national healthcare authority.