On Monday, Dr Prativa Pandey, medical director at the CIWEC Hospital and Travel Medicine Center, tested positive for Covid-19.

She had taken the first dose of Covid-19 vaccine six weeks ago, she said.

After mild symptoms like stuffy nose and low grade fever, she decided to get tested for the coronavirus. She tested positive.

“I have been liberal with my visits, attended parties and met people,” Pandey told the Post over the phone. “Now I feel bad, as I have exposed my two-year-old grandson as well as my family members and others to the risk of infection.”

Pandey’s admission is noteworthy, as when people are being too careless about the coronavirus infections, there are many who consider to be completely immune to the virus after getting the first dose of the vaccine.

It’s wrong to assume that the first dose of the vaccine protects people from the virus, experts say.

The World Health Organization says that Covishield vaccine, developed by the University of Oxford and pharmaceutical giant AstraZeneca, has an efficacy of 63.09 percent against the symptomatic SARS-CoV-2 infection after the first dose. Longer dose intervals of 8 to 12 weeks range are associated with greater vaccine efficacy.

“A reminder that a virus is out there waiting to catch us off-guard,” Dr Pandey wrote on her Facebook page on Tuesday. “I urge everyone to not let your guard down until most of us are immunised.”

Nepal launched its Covid-19 vaccination drive on January 27. The second phase of the immunisation campaign began on March 7. So far more than 1.1 million have been vaccinated including over 670,000 in the last three days after the government began the second phase of the campaign to inoculate those over 65.

Doctors say there is a need for people to understand what the efficacy of a vaccine means and the government authorities can do a better job by disseminating information about it while running awareness campaigns about taking the vaccine.

No vaccine can provide 100 percent protection and efficacy of any vaccine means by how many percentage points the jab can lower the risk of getting infected.

According to doctors, Covishield’s efficacy is 63.09 percent, which actually means those who have taken this vaccine are 63.09 percent less likely to be infected. This means, people must continue to take precautionary measures, they said.

Apart from this, infection status of individuals before immunisation also has a role in the infection after the immunisation. If the person is already infected and not aware of it or is in the incubation phase, he/she will test positive even after the immunisation.

Doctors say that it takes some time for the vaccine to make antibodies against the virus and if people come in close contact with the infected people after they are immunised, there will be a chance of getting infected.

“Even in America, several ‘breakthrough’ Covid-19 cases have been recorded after immunisation of Pfizer vaccine,” Dr Sher Bahadur Pun, chief of the Clinical Research unit at Sukraraj Tropical and Infectious Disease Hospital, told the Post. “We also have a chance of getting infected after immunisation unless the majority of the population is inoculated.”

Breakthrough Covid-19 cases mean someone getting reinfected with the virus more than two weeks after getting both doses of the vaccine.

Public health experts say the efficacy of the vaccine also depends on the variant of virus and vaccines made for one variant may not work against the new variant.

“We have South Africa’s example, which has put its roll-out of the Oxford-AstraZeneca vaccine on hold after the jabs showed minimal protection against its new Covid variant,” Dr Keshav Deuba, a public health epidemiologist, told the Post. “Without knowing the virus’ variant we are immunising the people.”

Doctors say if a new variant has developed in the country and the vaccine used does not work against, it will be a waste of resources only.

“We have been stressing on having the technology to identify the variant of virus in the country for months but I don’t think concerned officials have taken the suggestion into account,” added Deuba. “As the coronavirus is the RNA virus, it keeps changing and several new variants might have developed within the country.”

After the government lifted restrictions imposed to lessen the spread of the virus, life has become normal. People have even stopped wearing face masks, maintaining social distancing and washing hands. People have been attending parties and schools and offices have been opened but there is no agency to monitor whether people are following safety measures.

Doctors say one should not let their guards down until the majority of people are immunised.

“Wearing masks, maintaining social distance and hand washing do not cost much. These simple practices can prevent the spread of the virus,” Dr Megnath Dhimal, chief researcher at Nepal Health Research Council, told the Post. “As a lot of things about the coronavirus are still unknown, we need to follow the safety measures. And this applies to even those people who have been vaccinated.”

Public health experts have been asking authorities concerned to focus on awareness drive since the beginning of the ongoing coronavirus pandemic.

“Doctors and public health experts have got tired of asking the authorities concerned to focus on awareness drive,” Dr GD Thakur, former director at the Epidemiology and Disease Control Division, told the Post. “Authorities do not take experts’ suggestions positively.”

Pandey who got infected despite receiving the vaccine also urges caution.

“As the risk of infection is not over yet, we should not give up the precautions,” Pandey said . “We should avoid the gatherings and parties and follow the safety measures to keep ourselves and others safe.”