Why do many health workers who have been vaccinated against Covid-19 still get sick?

Associate Professor, Dr. Tran Dac Phu, former Director of the Department of Preventive Medicine (Ministry of Health), answered questions about the effectiveness of the Covid-19 vaccine after many staff members of the Ho Chi Minh City Hospital for Tropical Diseases who had been vaccinated still contracted Covid-19.

Reporter: Sir, many people are worried that they can still get infected with the SARS-CoV-2 virus after being vaccinated against Covid-19, for example, many staff members at the Ho Chi Minh City Hospital for Tropical Diseases contracted Covid-19 despite being vaccinated?

Associate Professor, Dr. Tran Dac Phu, former Director of the Department of Preventive Medicine (Ministry of Health), advisor to the Vietnam Center for Public Health Emergency Response : The Covid-19 vaccine is a new vaccine , licensed under emergency conditions, so we do not know for sure whether vaccination can reduce the possibility of infection and disease transmission. However, vaccination will help reduce severe symptoms and reduce the risk of death.

Vaccines do not provide absolute protection, especially against infection.

Currently, it is not clear how long it takes for antibodies to form after vaccination to be able to prevent disease.

In addition, vaccines do not provide absolute protection , especially the ability to prevent disease transmission. In fact, there are vaccines that are 90% effective, but there are vaccines that are only 50%-60% effective. This means that some people who have been vaccinated can still carry the virus and infect others.

So, can you rest assured that you are protected after receiving two doses of the Covid-19 vaccine?

As I said above, getting 2 doses of vaccine with the recommended time will give the body protective antibodies, but not everyone has them .

Furthermore, this is a new strain of the virus, so it will take time to study and evaluate whether this vaccine is effective in protecting against the Indian strain. However, it must be affirmed that when injecting the Covid-19 vaccine, if it does not prevent the transmission of the SARS-CoV-2 virus, the vaccine will reduce the severity and death of infected people.

Covid-19 vaccination is a very important proactive disease prevention measure. However, people who have been vaccinated against Covid-19 still need to be aware of the importance of limiting risky behaviors and strictly implementing epidemic prevention measures according to regulations, including 5K: masks, disinfection, distance, no gatherings, and medical declaration.

Vaccination takes 14 days to have initial effect

Covid-19 vaccines do not provide immediate protection. It takes at least 14 days after the first injection to start working, and the level of protection at that point is very low.

After the second injection, from 1 month or more, the vaccine will reach optimal protection and this effectiveness is only about 60% - 90% depending on the type of vaccine. Vaccines do not provide absolute protection, especially the ability to prevent disease transmission.

(Dr. Pham Quang Thai, National Institute of Hygiene and Epidemiology)