Booster shots likely needed, expert says
Immune response weakens over time
Individuals who have been fully vaccinated against Covid-19, as well as those who have fully recovered against the disease, are likely to need booster shots to maintain sufficient protection against reinfection, a virus expert is warning.
Yong Poovorawan, head of the Centre of Excellence in Clinical Virology of Chulalongkorn University, said in a Facebook post on Monday that a study into recovered patients suggested that immunity against Covid-19 begins to decrease around three to six months after being infected.
According to Dr Yong, a virus' incubation period plays a significant role in determining the effectiveness of a vaccine, which generally works better against vaccines with long incubation periods, such as measles and chicken pox.
However, similar to influenza, Covid-19 has a short incubation period at 2-7 days. As such, to maintain immunity against the disease, booster shots will be needed, he said.
The expert also warned that those who have been vaccinated, or acquired immunity against Covid-19 as a result of prior infections, can still be reinfected, although the symptoms in subsequent infections tend to be less severe.
"It is highly likely that a third dose of the Covid-19 vaccine will be needed and it is possible that people will need to get vaccinated against the coronavirus periodically," he wrote.
He said that the nation's inoculation programme is a must-do because vaccines are highly effective at preventing people from being hospitalised or dying from their symptoms.
According to the Centre for Covid-19 Situation Administration (CCSA), a total of 618,583 people received Covid-19 vaccines between Feb 28-April 18. On Sunday, 9,219 people received their first dose, while and 843 received their second dose.
Meanwhile, Sonthiya Sawasdee, adviser to the House committee on law, justice and human rights, on Monday filed a complaint with Technology Crime Suppression Division (TCSD) against Arunee Kasayanont, spokeswoman for the opposition Pheu Thai Party, over her comments on Saturday about the AstraZeneca vaccine.
He said Ms Arunee also allegedly posted part of her remarks on Facebook which can incorrectly lead the public to believe the vaccine is not effective.
Mr Sonthiya focused on her comment, "other people's trash is our treasure", which he said can affect public confidence in the vaccine.