Tuesday, March 15, 2022, 6:00 a.m.
The spread of the Omicron strain of COVID-19 has spread rapidly across the country. In addition to the characteristics of the species It is also due to the effectiveness and efficiency of the coronavirus vaccine. 19 per such species is greatly reduced. In those who have received 2 doses of vaccine for a period of time Therefore, additional booster shots should be given. To reduce the severity of the disease, especially the elderly and those with congenital diseases, including chronic respiratory disease coronary heart disease chronic kidney disease cerebrovascular disease Obesity, cancer, diabetes and immunocompromised people Those who are at risk of severe COVID-19, but currently only 30 percent of these patients received a third dose of vaccine, making the vast majority of those with severe symptoms and death still in the group. such The Royal College of Physicians of Thailand with the approval of the Executive Committee Therefore, I would like to announce the immunization vaccine based on the current academic evidence as follows:
1. People who have not received the vaccine or have not received 2 doses should be vaccinated as soon as possible. It is a vector virus vaccine, namely AstraZeneca vaccine or mRNA vaccine, including at least 2 doses of Pfizer or Moderna vaccine.
2. People who have received two doses of inactivated inactivated vaccines, either Sinovac vaccine or Sinofarm vaccine, have evidence that their immunity is reduced so rapidly that they cannot prevent infection or serious illness and death from COVID-19, Omicron strain Therefore, the 3rd dose of immunization with vector or mRNA vaccine should be given after more than 1 month after the 2nd dose, and the 4th dose after 3 months after the third dose.
3. Persons who have received 2 doses of vector viral vaccine or mRNA vaccine, i.e. 2 doses of AstraZeneca vaccine, 2 doses of Pfizer vaccine or 2 doses of Moderna vaccine, have evidence of immunity. The resistance to omikron strain was greatly reduced after 3 months in those who received the Astrazeneca vaccine. Therefore, mRNA immunization should be given after the second dose for more than 3 months. In the case of two doses of mRNA vaccine, mRNA immunization should be given after the second dose. longer than 6 months
4. Persons who received 2 complete doses of cross-formula vaccine, namely attenuated vaccine and vector virus vaccine. or inactivated vaccines and mRNA vaccines or vector virus vaccines and mRNA vaccines. Studies in Thailand have shown that immunity to omikron strains is significantly reduced compared to delta strains. in those who received cross-formula with inactivated vaccine therefore should be immunized with mRNA vaccine (optional as viral vector vaccine) If the second dose is a vector virus vaccine or in people who do not need the mRNA vaccine) after more than 3 months after the second dose, mRNA should be boosted after the second dose. for more than 6 months in subjects receiving cross-formula of vector viral vaccine and mRNA vaccine.
5. Safety of 3rd dose booster vaccination At present, the 3rd dose booster vaccine is widely used in many countries including Thailand. with adverse reactions from the second dose of vaccination which, when considered The benefits of vaccination in preventing infection especially to prevent severe disease symptoms and death more than the negative effects of vaccines. Experts therefore recommend getting the 3rd dose of booster vaccine.
6. All types of COVID-19 vaccines, including the 3rd dose booster vaccine, do not completely protect against COVID-19. but reduces hospitalization pneumonia use of a ventilator and death Therefore, there is still a need to prevent disease through practice, such as avoidance at the community. No ventilation, social distancing, washing hands and wearing masks properly.
7. Screening of immunity to the pathogen that causes COVID-19 (SARS-CoV-2) is not recommended to assess the effectiveness of vaccines given for the prevention of COVID-19. or used in the consideration of getting a booster dose of the COVID-19 vaccine because each type of immunity test is different in interpreting the results. Immunity levels are reduced after the second dose of vaccination, and there is no immune level that predicts efficacy and efficacy against omikron strains. including the aforementioned examination The cellular immunity of the vaccine cannot be assessed, and it may also be misleading to protect against infection. Therefore, this should only be done in research.
Air Chief Marshal Anutara Chittinan, MD.
President of the Royal College of Physicians of Thailand