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Without a vaccine Coronavirus can have disastrous consequences

 

 

 

Rayhan Ahmed Topader:

 

Coronavirus continue to increase across the world, many people are asking whether so-called herd immunity might be the best strategy to defeat the disease. Public health experts say talk of herd immunity is premature until we have a vaccine for the deadly virus. Here’s what you need to know: Herd immunity, or community immunity, happens when a sufficient proportion of a population is immune to an infectious disease through vaccination or prior illness to make its spread from person to person unlikely, according to the Centers for Disease Control and Prevention. Even individuals not vaccinated are offered some protection because the disease has little opportunity to spread within the community.This assumes that Covid-19 immunity through infection is long-lasting, said Christelle Ilboudo, MD, infectious disease expert at MU Health Care. Some studies have shown a progressive decline in antibodies after infection with other types of coronaviruses, but scientists are still not certain whether infection provides long-term protection from the virus. Since symptomless people can transmit the infection as carriers, protective measures become the matter of utmost importance. We are ignoring the fact that even a downward trend of new cases, as we are seeing, can take a U-turn.
Also any time especially during winter a second wave or existing pattern could change. The study shows the majority of people have no symptoms and 18 per cent of them are children, so opening schools at this stage can be catastrophic, considering child population. It is wise to wait and watch. Many study showed, the spread of Covid-19 in the slum areas of Dhaka where the majority of people have already been infected and developed antibodies, suggests that it has almost achieved herd immunity naturally by getting exposed to the virus. It has revealed that one in ten of Dhaka’s population has been exposed to the Coronavirus and has developed antibodies. More representative samples covering different regions, hotspots of our country have to be carried out immediately.

In the case of Covid-19, we don’t know if or when a vaccine will be available. We also don’t know whether everyone who recovers is necessarily immune, if yes for how long may vary. Herd immunity refers to a large portion of a community developing a degree of immunity to a virus, thereby reducing person-to-person spread. As a result, the whole community gains protection, not just those who are immune. Also herd immunity, an important tool in epidemic control, was proposed as a means to overcome pandemic.

Only a certain proportion of the population needs to be infected in order to stop large outbreaks. Either through naturally-acquired disease, or through vaccination. Since a vaccine is not available for Covid-19 yet, some people advocated that the infection be allowed to spread in the community until herd immunity is achieved. At least 60-70 per cent of the population should have immunity to really break the chain of transmission. If you allow this to happen naturally, it will take a long time, of course, but more importantly, it is going to do a lot of collateral damage. The World Health Organisation said in a statement, there is currently no evidence that people who have recovered from Since symptomless people can transmit the infection as carriers, protective measures become the matter of utmost importance. We are ignoring the fact that even a downward trend of new cases, as we are seeing, can take a U-turn, any time especially during winter a second wave or existing pattern could change. The study shows the majority of people have no symptoms and 18 per cent of them are children, so opening schools at this stage can be catastrophic, considering child population. It is wise to wait and watch. Covid-19 and have antibodies are protected from a second infection.

Many countries have already been infected by the second wave, if we are not on our guards anything yet could happen. There have been cases of second time infected. If this finding is correct, it means in real terms that millions of people have been infected so far, which is way above the actual diagnosed numbers. If these many are already infected despite all control measures including lockdown, then Dhaka is moving closer to undeclared herd immunity. If the same trend were to continue, Dhaka might go onto attain herd immunity soon. Antibody level remains high for only three months in corona, so it is impossible for herd immunity to persist without a vaccine for long. Aiming for herd immunity without a vaccine can have disastrous consequences. Herd immunity is achieved when one infected person in a population generates less than one secondary case on an average, which corresponds to the effective reproduction number R dropping below 1 in the absence of interventions. Given the population, herd immunity could not be an option. Yes, herd immunity could be achieved through immunization, but that may be in the future. For now, we have to follow Covid-19

appropriate behaviour like wearing masks, avoiding atherings, following hand hygiene, and maintaining social distancing.Infectious diseases have been known to reach herd immunity.

With a vaccine one can achieve immunity and herd immunity safely. Natural infection also can achieve at some point, but it would be at a serious human cost. Meanwhile, until a vaccine reaches in hand they shall have to show efficacy. It shall be the best to take actions that would slow down the progress of the virus following Covid-19 etiquettes of wearing a mask, physical distancing, and following hand hygiene. Vaccines are particularly suited for creating herd immunity because; they can be specifically targeted to highly exposed populations, such as healthcare workers or individuals with frequent contacts, exposure, and service providers. They may have a significantly greater impact on reducing viral circulation than naturally-acquired immunity, especially if it turns out that naturally-acquired protective immunity requires boosts through re-infections. Herd immunity is a concept based on the body’s immune resistance to the spread of a contagious disease within a population.

It is achieved when a significantly high proportion of individuals are vaccinated against it and therefore develop immunity. When enough people are vaccinated, a virus is unable to spread through the population. Immunity can be acquired through infection or through vaccination-if a vaccine is available.

A population has achieved herd immunity when a large enough percentage of individuals become immune to a disease. When this happens, infected people are no longer able to transmit the disease, and the epidemic will burn out. As a professor of behavioral and community health sciences, acutely aware that mental, social and economic health are important for a person to thrive, and that public health measures such as social distancing have imposed severe restrictions on daily life. Dropping social distancing and mask wearing, reopening restaurants and allowing large gatherings will result in overwhelmed hospital systems and skyrocketing mortality. Furthermore, according to recent research, this reckless approach is unlikely to even produce the herd immunity that’s the whole point of such a plan. Vaccination, in comparison, offers a much safer and likely more effective approach.

Writer and Columnist     raihan567@yahoo.com