Nepal Health Research Council has launched a study on the protection level of Covid-19 vaccine on immunised people.

The council said that the results of such a study will help the authorities ascertain the protection level of vaccines and take decisions on administering booster shots.

“The study is in its final phase and we will most likely unveil results after two weeks,” Dr Megnath Dhimal, chief researcher at the council, told the Post.

Nepal launched its Covid-19 vaccination campaign on January 27 this year with one million doses of Covishield, the AstraZeneca type vaccine, gifted by India.

In the first phase of the vaccination drive, frontline workers including health workers, sanitation workers, hospital staffers, security personnel deployed in prisons, and elderly people residing in old-age homes were vaccinated.

The first phase of the vaccination drive continued until March 4 in which journalists, people serving in diplomatic missions, lawmakers and bureaucrats among others were inoculated. The second phase of the drive was started on March 7.

Experts have been laying stress on the need to start administering booster shots, at least to the elderly people and frontline workers.

“Our study will show how long a particular vaccine works effectively and when booster shots will be required,” said Dhimal.

Some developed countries including the United States have already started administering booster shots to their adult population.

Doctors say it’s time the authorities in Nepal started administering booster shots as well. The government, however, has not taken any decision in this regard.

“Scientifically, booster shots are needed,” said Dr Bhagwan Koirala, chairman of the Nepal Medical Council, the national regulatory body of medical doctors. “But if we start giving booster shots, it will be unfair to those who have not received even the first shot of two-dose vaccines.”

According to Koirala, authorities must make a prudent decision while launching booster shots.

“Booster shots should be started after vaccine coverage reaches a certain point, or after a certain percentage of people have been vaccinated,” said Koirala.

Nepal so far has used double-shot AstraZeneca, Vero Cell, Pfizer-BioNTech and Moderna vaccines and the single-shot Janssen vaccine to inoculate its population against Covid-19.

Nepal had received 1,534,850 doses of Janssen from the United States on July 12. But the government has not released data of how many doses were administered. The wastage is said to be 5 percent.

So far, 9,302,019 people (30.6 percent of the total population) have been fully vaccinated.

Nepal needs to vaccinate around 78 percent of its over 30 million estimated population, or around 25 million people, as per the government’s new plan that includes those aged between 12 and 18 years. Earlier, the government had planned to vaccinate only those aged 15 years and above.

As of Sunday, Nepal has received 29,113,040 doses of Covid-19 vaccines—Vero Cell, AstraZeneca, Janssen, Pfizer-BioNTech and Moderna.

In the last 24 hours, three people died of Covid-19 infections. The Health Ministry said that 341 people (313 in 10,416 polymerase chain reaction tests and 28 in 2,820 antigen tests) tested positive on Monday.

Active cases stand at 5,824 throughout the country.

The Ministry of Health and Population has decided to provide “extended shots” to those who are immuno-compromised and those above 6o years of age who have taken the Vero Cell vaccine.

These additional doses are not booster shots, according to the Health Ministry.

Certain groups with compromised immunity—cancer patients, those who underwent organ transplantation, people living with HIV and those on immunosuppressants—will be administered these extended shots, which are considered part of a series of primary doses.

Healthy adults need two doses and those having suppressed immunity need an additional dose, officials said.

The World Health Organisation says an additional dose may be needed as part of extended primary series for the target population where immune response rate following the standard primary series is deemed insufficient. The objective of an additional dose in the primary series is to optimise or enhance the immune response to establish a sufficient level of effectiveness against disease.

“In particular, immunocompromised individuals often fail to mount a protective immune response after standard primary series [two doses], but also older adults may respond poorly to standard primary series,” reads the WHO’s interim statement.

The United States, the United Kingdom, Japan, Israel, Canada, Germany, France, Italy and others have started booster shots to their people.

Public health experts have been pressing for administering booster shots almost immediately due to the emergence of the Omicron variant of the coronavirus.

Though much is still unknown about Omicron, most experts agree that a booster shot may provide additional protection.

“Developed countries have already started providing booster shots,” said Dr Keshab Deuba, a public health epidemiologist. “The protection level developed from the Covid-19 vaccine wanes after a certain period. We also have to start the booster shots, but we don’t know how long it will take.”

Booster shots can be given to eligible people after six months of the administration of the second vaccine dose. Some countries have been administering booster shots of all vaccines after three months of the completion of the second dose.

The US Food and Drug Administration, according to the New York Times, has authorised booster shots for people aged 16 or older who received their second dose of the Pfizer-BioNTech or Moderna vaccines at least six months ago. People who received the single-dose of Johnson & Johnson vaccine are eligible for boosters just two months after their shot, the paper reported.

The waiting time could, however, vary depending on individual decisions of the countries.

The Australian government, according to the Guardian, has reduced the waiting time for Covid-19 vaccine booster shots from six months to five in a bid to keep people protected against the virus and slow its spread as the Omicron variant emerges.

The level of antibodies against Covid-19 in individuals who are fully vaccinated with Vero Cell and Covishield vaccines drops after 60 days, a study carried out by the Nepal Health Research Council in the past had shown.

The study revealed the continued presence of antibodies for 150 days among the fully vaccinated individuals but at a reduced level. It was also found that the level of antibodies grows in the first 60 days.

The study was conducted among 1,796 people in Kathmandu Valley. As many as 81 percent of the study subjects were vaccinated and the rest were unvaccinated. Their antibody samples were taken between May 31 and July 1.

Doctors say studies should be carried out about the protection level of all Covid-19 vaccines, which not only provide the information but also helps in planning and policy formulation.

“We do not know the protection level of the people who were vaccinated in the initial stage (January-February),” said Dr Sher Bahadur Pun, chief of Clinical Research Unit at Sukraraj Tropical and Infectious Disease Hospital. “If the protection level has declined on those people, they are at high risk of infection. Without booster shots, chances of frontline workers getting infected are high and they can also transmit the virus to others.”