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May 26 2021

Herd Immunity: What Does It Take to Achieve It?

The COVID-19 pandemic sent the world into a tailspin, resulting in more than 153 million cases and over three million deaths as of this writing. Some countries were able to deal with the challenging year better than others. For instance, Taiwan had just over a thousand cases and 12 deaths since the pandemic started. However, some countries are experiencing worse.
In the Philippines, there are now more than a million cases and over 17,000 deaths. The government works at managing the situation ever since the virus spread at the beginning of 2020. Now, with new virus variants developing, lockdowns and quarantine protocols are being implemented once again to stop the surge of infections as it recently reached the highest number of cases in Southeast Asia.
No one was immune from the coronavirus when it spread like wildfire across the globe. But thanks to brilliant scientists and researchers, several vaccines are now available to strengthen the body to fight COVID-19 infection, reduce the risk of severe illness and death, and the ultimate goal to beat the virus: achieve herd immunity.

What is Herd Immunity?

Herd immunity or “population immunity” or “herd protection” is a concept where a virus can no longer infect people easily because most of the population is made immune to it either through vaccination or immunity as a result of a previous infection.
For example, if 80% of a population has been vaccinated, resulting in immunity to a virus, four (4) out of five (5) people who interacted with someone infected would not get sick. It is noteworthy, however, that those who are already immune to the infection can still be carriers of the virus. When herd immunity is achieved, the transmission of COVID-19 is more controlled.
Since COVID-19 is highly contagious, the greater the proportion of people who achieve a certain degree of immunity to it, the higher the chances of significantly stopping the spread. In the Philippines, according to vaccine czar Carlito Galvez Jr., the government aims to vaccinate about 75 to 80% of the population to achieve herd immunity, aiming to achieve this by 2023.

What Does It Take to Achieve Herd Immunity?

There are two ways to reach herd immunity for the novel coronavirus or any infectious agent: natural infection and vaccination.
  • Natural Infection

People can develop resistance to the virus through natural immunity. When the body gets exposed and eventually recovers from an infectious disease, its natural response is to make antibodies to fight off the virus or bacteria. Typically, those who survived the infection may be rendered immune to future contraction.
The challenges: While natural immunity has a similar effect to vaccination, it presents great risk and could result in widespread infection and, worse, death. It is not guaranteed how long an individual is protected from reinfection after recovering from the virus. Even with antibodies, there is still a chance that the person can get infected with COVID-19 again.
Relying on community infection could also quickly overwhelm the healthcare system. Around 70% of the population would have to recover from COVID-19 to fight the pandemic. When the number of infections rises and affects people at high risk (e.g., older people and those with existing medical conditions), it can do more harm than good.
  • Vaccination

Herd immunity can also be achieved through vaccination. Vaccines are administered as a preventive measure to help the body develop immunity to the virus safely, without causing illness. People who have been vaccinated are protected from contagion and lessens the risk of passing on the virus, breaking the chain of transmission. 
The challenges: Achieving herd immunity through vaccination to fight COVID-19 could be challenging for various reasons.
  • Hesitant public - The public is not convinced or may be reluctant to take the vaccine due to different reasons. These include religious objections, fear about the side effects, and skepticism about its effectiveness despite the vaccines being approved for safe use by health experts after going through rigorous testing and clinical trials.
  • Supply and option availability - The rollout of vaccines varies among and within nations. If a specific community reaches a high vaccination rate, but its neighboring areas fall behind, outbreaks can still occur when the communities mix. This makes it crucial to still observe proper health protocols even after getting vaccinated.
  • Efficacy concerns - It is not yet known how long the current vaccines can protect people from the novel coronavirus since efficacy rates also vary. In addition, there are new COVID-19 variants as a result of mutation, which may be resistant to the current vaccines.
Herd immunity through vaccination requires a collective effort. It will work best if more people are vaccinated as quickly as possible while still observing physical distancing, wearing masks, and doing other safety measures to maintain lower infection rates.

Herd Immunity: The Key to Widespread Protection

Getting vaccinated is a huge step forward in protecting oneself and others from the novel coronavirus. Take the opportunity once the vaccine becomes available for you. Until the COVID-19 virus is completely eradicated, consistently observing minimum health protocols to reduce the spread of the virus even if you have been vaccinated.
For more information about how to fight immune system diseases and the diagnosis, treatment, or management of COVID-19, get in touch with Makati Medical Center today.