Many people get Covid-19 when ‘not enough time to create antibodies after injection’

Of more than 500 Covid patients treated at Military Hospital 175, about 20.5% had a vaccine injection less than 4 weeks before the disease was detected; 3.8% injected two full doses.

Colonel, Doctor Vu Dinh An, Deputy Director of the Intensive Care Unit and Deputy Director of the Covid-19 Treatment Center, Military Hospital 175, said the hospital’s survey showed that 3.8% F0 Here, two doses of the vaccine have been administered, but the second dose has not yet responded to the full immune response, which is not enough for at least 15 days after the second injection.

“People who get the first dose of less than 4 weeks do not have enough time to create antibodies, so the infection rate is high. In the case of two injections, the rate of Covid-19 is much lower,” said Dr. An. The study also showed that at Hospital 175, the vaccinated F0 had milder disease symptoms than the unvaccinated.

Major General, Associate Professor Nguyen Hong Son, Director of Military Medical Hospital 175, said: “It is important that the time is from vaccination to illness, if there is not enough time for the body to create antibodies after the illness. injection, the risk of infection is still very high.” Mr. Son also said that the patient had received two full doses, the protective effect of the vaccine was great, avoiding the risk of severe transfer.

Cho Ray Hospital also recorded many Covid-19 patients hospitalized after receiving one dose of vaccine, or two injections but less than four weeks. However, the hospital does not have specific statistics on this number.

According to Dr. Le Quoc Hung, Head of the Department of Tropical Diseases, Cho Ray Hospital, who injects a vaccine, the body just begins to create antibodies but not enough protection, so the risk of getting sick and getting worse still not much different from people who have not been vaccinated.

“People who receive two injections, if it is not enough 4 weeks, still have a high chance of getting the disease, the possibility of severe progression still occurs, especially those with underlying diseases”, said Dr. protection depends on different vaccines. “Do not be subjective after vaccination,” emphasized Dr. Hung.

According to the recommendations of the World Health Organization (WHO), after receiving a full dose of Covid-19 vaccine, the body needs a few weeks to generate immunity. Some cases can be infected while the body is building full immunity. No vaccine is 100% effective. A small number of people who have been vaccinated can still get the disease, but the illness is usually mild, with no serious progression or death.

According to the manufacturer’s instructions, the interval between two doses of AstraZeneca vaccine is a minimum of 4 weeks, preferably 8-12 weeks. Two doses of Moderna vaccine are given at least 4 weeks apart. The Pfizer vaccine is given as two shots at least 3 weeks apart. Two doses of Sinopharm vaccine 3-4 weeks apart.

Doctor, Doctor Nguyen Van Vinh Chau, Deputy Director of Ho Chi Minh City Department of Health, Director of Ho Chi Minh City Hospital for Tropical Diseases, at a press conference in mid-August, said that vaccines injected into the body will create antibodies. neutralizing antibodies to the virus, this antibody is produced from the second week after injection.

According to Dr. Chau, there is no vaccine that blocks 100% of the virus, but antibodies from the vaccine will help prevent the virus from entering cells, reducing the process of causing cell damage to organs in the body. Therefore, those who have been vaccinated with protective antibodies have a reduced chance of contracting Covid-19; if they have mild symptoms, they are less likely to get serious and die. death.

“Many people think that getting two shots of the vaccine will not get Covid-19, which is wrong,” said Dr. Chau. According to Dr. Chau, over the past time, there have been many cases in Vietnam and the world that have received two doses of the vaccine but still contracted Covid-19, because the virus strains are getting stronger and may be resistant to disease. vaccines.

The vaccine helps reduce the severity of the disease, but not 100% without the disease, Dr. Chau analyzed. Therefore, even though people have been vaccinated, people should still strictly follow the 5K regulations and distance themselves to avoid infection.

As of August 30, Ho Chi Minh City has injected more than 6.1 million doses of vaccine, of which nearly 5.8 million people received the first dose, 337,134 people received the second dose.

Health workers prepare doses of vaccines for people in Ho Chi Minh City, August 15. Photo: Thanh Nguyen

Announced in July of Global Alliance for Vaccines and Immunizations (GAVI) on the protective efficacy of vaccines against Covid-19 after clinical studies are as follows:

The protective efficacy against symptomatic Covid-19 disease after a single dose of AstraZeneca vaccine is 73%, Moderna is 85%, Pfizer is 82%.

Protection against severe Covid-19 disease or hospitalization from 21 days after the first dose of AstraZeneca vaccine is 100%, Moderna is 100%, Pfizer is 83%, Sinopharm is 79%.

The protective efficacy against symptomatic Covid-19 after two doses of AstraZeneca vaccine was 67%, that of Moderna was 95%, Pfizer was 94%, Sinopharm was 78%.

These studies were conducted under different conditions in terms of sample size, country, and Covid-19 spread at the time of the study, so it is not possible to “make head-to-head comparisons” to assess the effectiveness between the two studies. vaccines together.

Le Phuong