American biotechnology firm Moderna said in a statement on Monday that in vitro tests have shown that the booster dose of the company’s Covid-19 vaccine is effective against the rapidly spreading Omicron variant, and that the currently used formula of the vaccine continues to form Moderna’s “first line of defense against Omicron.” reportedly will.
Moderna noted that the rapid deployment of Omicron was instrumental in its decision to continue focusing on the currently used formula of the vaccine, known as mRNA-1273. Noting that a vaccine development plan that will only protect against Omicron is still valid, Moderna stated that it is hoped to start clinical trials of the Omicron vaccine at the beginning of 2022.
Moderna’s chief medical officer, Dr. Paul Burton, in an interview, said, “We currently have 1273. This vaccine has a high efficacy rate and the vaccine is extremely safe. I think it will provide protection during the Christmas period and winter months, when we will feel the heaviest pressure from Omicron.”
Moderna noted that two doses of the vaccine produced low levels of inactivating antibodies against the Omicron variant, but a booster dose of 50 micrograms increased antibody levels 37-fold. It was announced that the 100 microgram booster dose of the same vaccine increased the antibody level 80 times.
The data, which has not yet been evaluated by independent scientific committees, is based on blood samples from people vaccinated against an artificial virus that mimics the Omicron variant.
Moderna’s Dr. Burton said that governments and health officials will decide whether the level of protection provided by the 100 microgram dose of the vaccine is preferred.
The firm reported that a booster dose of 100 micrograms is generally safe, but there has been a slight upward trend in the incidence of side effects.
Moderna also stated that it has tested the efficacy of the vaccine against booster vaccine prototypes targeting several previous variants of concern, and the results were the same.
The 50 microgram booster dose of Moderna was approved by US health officials in October. The first two doses of the Moderna vaccine are administered as 100 micrograms.
Both the Moderna and Pfizer/BioNTech vaccines were found to be associated with heart inflammation, a very rare side effect seen especially in young men. Some studies have revealed that the Moderna vaccine has a higher risk of causing heart inflammation than Pfizer.
The highly contagious Omicron variant, first detected in South Africa and Hong Kong at the end of November, has been found in 89 countries so far, according to the World Health Organization (WHO) statement on Saturday.
WHO noted that Omicron cases doubled in one and a half to 3 days in areas with community transmission, but questions about Omicron still remain open on many issues, including the severity of the disease.
Decision from some countries to shorten the booster vaccination schedule
To counter the new wave of infections caused by the Omicron variant, the number of countries that have decided to reduce the duration of the third dose booster vaccine from six months to three months is increasing.
The faster spread of Omicron than the previous dominant variant, Delta, and the higher risk of reinfecting those who are fully vaccinated or have had a past Covid, have paved the way for booster vaccines to be made earlier than expected. However, some experts say that getting booster vaccines early will reduce the long-term protection of the vaccine.
Although data are limited, some laboratory studies show that two-dose Covid-19 vaccines are not enough to stop infections caused by the Omicron variant, and a booster dose is needed.
Studies conducted in South Africa and the UK show that the Omicron variant is spreading very quickly, and the Delta variant will soon replace it in a few countries. Experts are also trying to determine how severe the Omicron cases are.
Many countries, including the United States, have approved the third booster dose for those six months after the second dose of the Covid-19 vaccine. This month, South Korea, the United Kingdom, and Thailand have increased their booster dose schedule from six months to three months. Belgium, on the other hand, has set the time period for the second dose to pass before the booster vaccine is four months.
France, Singapore, Taiwan, Italy and Australia have reduced the waiting period for booster vaccines to five months.
The USA, South Africa and Germany still apply the rule of waiting six months after the second dose before giving the booster vaccine.
While Finland recommends a three-month booster dose for people at risk, shortening it for the general population will not work in slowing rising hospitalization rates.
Spain and Lithuania, on the other hand, give booster doses only to those with weakened immune systems and the elderly. India has yet to decide on launching a booster vaccination campaign. The WHO, which called on rich countries before and noted that the first dose of vaccines should be given to the citizens of poor countries, started to look more favorably on supplemental vaccines due to the rapid increase in the number of cases.
“Shortening the booster dose may reduce the effect of the vaccine”
Experts note that shortening the time required for the booster dose poses a risk that the vaccines administered in multiple doses may harm the effectiveness. However, more data is needed to come to a firm conclusion on this issue.
Infectious diseases specialist at Vanderbilt University School of Medicine, Dr. “For multi-dose vaccines, in general, the immune system functions better when the vaccine is given time to mature,” said William Schaffner.
Although research shows that booster vaccines temporarily increase the level of antibodies, experts emphasize that the purpose of vaccines is to reveal not only antibodies, but also elements that form the second line of immune system defense, such as T cells.
Multi-dose vaccines give the immune system time to line up its supportive defenses.
Former director of the US Food and Drug Administration, Dr. “I’m worried about what effect this will have on the maturation of the immune system. Three months feels like too short,” Luciano Borio said.
Kristeen Nordlund, spokesperson for the US Centers for Disease Control and Prevention (CDC), noted that the US has no plans to change its recommendation on the duration of booster vaccination.
A spokesperson for the Arkansas State Department of Public Health said: “When you look at it from the immunological side, there is no point in keeping the time required for a booster vaccine shorter than six months.”
However, some experts underline that it is not planned to set the time to wait for a booster dose to be six months. Experts note that data collected before the rise of the Omicron variant in November began to decline in the past four months after immunization, as measured by antibody levels.
Director of the Scripps Research Institute in California, Dr. Eric Topol said, “After four months, the decrease in the effectiveness of the vaccine really started to become evident. Omicron strengthens it.”