Covid-19 Pandemic: What if I Can’t Produce a Vaccine?

There is 175 or more Covid-19 vaccine in development. Almost all government strategies to deal with Coronavirus The pandemic is based on the idea that one of these vaccine candidates will ultimately provide broad protection against the virus, allowing us all to return to normal life.

However, there is no guarantee that this will happen. But Most promising caseI’m still not sure if any vaccine can prevent Covid-19 from being caught forever and eradicate the disease over time, or at least contain it in a limited outbreak. Vaccines reduce the severity of symptoms or provide temporary protection. What if this is the case?

Some people claimed that when a sufficient population captured Covid-19 and generated an immune response against it, we reached “herd immunity” and the virus could no longer spread. However, this is a misunderstanding of what immunity of the herd means and how the virus spreads, not the practical purpose of controlling Covid-19.

Collective immunity makes it possible to eradicate the disease using vaccines. Percentage of population needing vaccination to reach herd immunity Will be calculated Use the basic fertility rate (R0).

This is the average number of people with each illness that naturally spread without medical or public health intervention, given the infectivity and spread of the illness.

The higher the R0 number, the more people need to be immunized by vaccination to stop the spread. We also have to take into account the fact that for medical reasons some people cannot get the vaccine. Some reject it..

Many illnesses have been eradicated in many countries thanks to the herd immunity provided by vaccination programs. However, herd immunity cannot be achieved by natural infection.

Let’s look at an example of measles caused by a virus that has spread to humans for centuries. It is very infectious – the R0 value is 15. This means that one measles child can infect 15 on average. as a result, About 95% To achieve herd immunity, people need to resist disease.

Most people who recover from a measles infection produce a good immune response that protects them over their lifetime. Nevertheless, before vaccination, measles was a very common childhood disease.

Each new generation of children was susceptible, and not enough people naturally began to resist the development of herd immunity.

In the 1930s, Temporary herd immune effect Recorded somewhere in the United States. But this is an exception, because most countries have developed universal measles vaccination programs. Get rid of illness..

Scientist thinks SARS-CoV-2 has an R0 value between 4 and 6 and is similar to rubella virus. The level of vaccination required to create herd immunity to rubella and eliminate rubella is 85%.

We know that Other coronaviruses (Including sir, mer, and some cold viruses), it does not cause a persistent immune response like measles. And Research on COVID-19 Even hotspots with numerous cases and deaths in the last few months show that less than 10% of the population show evidence of an immune response from infection.

This suggests that the natural proportion of resistance is far from 85%, which may be required for herd immunity. And that means that without a vaccine, the virus could be endemic and could be permanently present in the population, like the coronavirus that causes a cold.

Study show Some people can get the same strain with the same cold Coronavirus At least once a year. COVID-19 is also seen in most countries, even though they believe infection is being suppressed to some extent.

Thus, the ongoing pattern of COVID-19 may be a more localized pocket of infection, and more cases may occur in winter. However, unless the first case is quickly found and isolated, these pockets will probably span a fairly large geographical area.

This is why continued use is essential Public health measures You can easily reduce the new epidemic by reducing the virus to very low levels, such as social distances, wearing masks, and washing your hands.

Ideally, if this were successful, the virus could eventually become extinct because it could not spread, as it did with the SARS-CoV virus behind it. Outbreak of Thurs 2002-2004.. However, COVID-19 is far more contagious and less deadly, and therefore much more difficult to control than Sars, and can be removed this way. May not be possible..

given that 700,000 or more COVID-19 has died in the world so far, many people have reported Long-term illness Even if the virus becomes endemic as a result of the disease, you should try to prevent as many infections as possible. Vaccines can provide a way to end the pandemic, but without the prospect of natural herd immunity, we would be long faced with the threat of COVID-19.

Sarah pit, Senior Lecturer, Microbiology and Biomedical Sciences Practice, Fellow of Biomedical Research Institute, Brighton University

This article is reissued from conversation Under Creative Commons license. Read Original work..