Bangladesh far from herd immunity; only mass vaccination can help: experts
Achieving herd immunity through a mass vaccination drive can be the best option for Bangladesh to check the deadly coronavirus as all the steps implemented so far, including lockdown, have failed to slow down its surge in the country, experts have said.
Though many are believed to have developed antibodies through infections, Bangladesh is not on its way to achieving herd immunity as new Covid-19 variants, like the South African one, can wreak havoc, according to the experts.
They think the government should focus mainly on collecting at least 250 million doses of Covid-19 vaccine from different sources to attain herd immunity.
They also said though some studies have raised questions about the efficacy of the Oxford-AstraZeneca vaccine against the South African variant, most studies suggest it can at least reduce the mortality and morbidity rates.
Herd immunity is a concept based on the body's immune resistance to the spread of a deadly disease or virus and it can be attained in two ways -- naturally or through infections of the majority population and artificially or through vaccinating at least 70 percent of the population of a country.
Far from herd immunity
Talking to UNB, Prof Muzaherul Huq, a former adviser to WHO South-East Asia region, said Bangladesh is not moving towards attaining herd immunity for lack of a strong vaccination drive.
"Only around 5.5 million people have so far received the first dose of Covid-19 vaccine. The official figure of the virus cases is only 673,594. We don't know how many people here have the antibody. So, we have an option to vaccinate majority people for attaining herd immunity," he observed.
Noted virologist Prof Nazrul Islam said though many people have developed some extent of immunity due to infection, Bangladesh is not heading towards herd immunity.
"The antibody that developed among our people through infections of the Italian variant looks to be ineffective against the South African one," he said.
Though the official figure of Covid-19 cases is very low, Prof Nazrul thinks a substantial number of the population of Bangladesh have already been infected with different variants of the virus and have the antibody. "But we're not sure whether such antibodies can immunise people from different variants as we're hearing about reinfections."
What should be done?
Prof Muzaherul said, "We must collect 250 million jabs to vaccinate around 125 million people to attain herd immunity in Bangladesh. The government should work out strategies in this regard. Or else, it won't be possible to control the spread of the virus in a country like Bangladesh where most people are reluctant to maintain health safety rules."
He said the government should look for alternative sources of vaccine to ensure it for the country's majority population within a short time.
Once the government can ensure vaccine for at least 125 million people, Muzaherul said, the new variants will not be a major concern for Bangladesh. "When the new variants will appear, new vaccines will also be developed. The infections of the virus caused by new variants will be very low when herd immunity will be achieved through a massive vaccination programme."
Global herd immunity essential
Additional Director General of DGHS, Professor Meerjady Sabrina Flora, said Bangladesh does not believe in a policy of achieving herd immunity through infection of its vast population.
"We're working for prevention of infections. We should never expect to get herd immunity through infections as it'll lead to many deaths," she said.
Flora said there should be a target of having herd immunity through vaccination. "But there's a challenge to ensure vaccines for all countries. We need global herd immunity. One single country cannot protect its population from the virus by gaining herd immunity if the virus continues to mutate in other countries."
"Now we have connectivity with different countries all over the world. So, it's difficult to resist the entry of new virus variants in our country. In fact, no country can do it alone. So, global herd immunity is necessary," she observed.
The DGHS ADG also said global herd immunity is possible if vaccination can be ensured for all countries based on equity.
Reinfection a new worry
Flora said there is a chance of reinfection of the coronavirus with the prevalence of new variants. "We can't make any final comment about Covid-19 as we see new information and findings about its different natures are coming out every day. Those who were infected with the virus earlier can be reinfected. So, everyone, including Covid-19 survivors, should always strictly adhere to health safety rules."
She said no one should ignore health guidelines in any way in the hope that they have antibodies through the infections of the virus. "It's essential for us all to keep ourselves protected through maintaining health rules."
Public health expert MH Chowdhury Lenin, chairman of the medicine department at the Health and Hope Hospital, said those who are getting infected now are mostly being infected with the foreign variants.
He said the new foreign variants also can infect people who have the antibody they developed with infections earlier.
Lenin said they are finding many cases of reinfection caused by the new variants. "People who were infected with the conventional virus are again falling victims to the new variants."
"So, we need to intensify the ongoing vaccine drive. Besides, we must maintain health safety rules, wear masks, wash hands and change our food habit," the expert said.
He said people should take fresh vegetables, seasonal fruits and protein regularly to boost their immune system.