The most effective Covid-19 vaccine strategy

Governments and researchers are working to find the most effective Covid-19 vaccination deployment strategies to quickly create herd immunity.

Governments, medical experts and researchers are working to find the most effective strategies to deploy Covid-19 vaccination to quickly create herd immunity as the pandemic continues to sweep the world. limited supply of vaccines. According to the journal Nature, the world needs about 11 billion doses of Covid-19 vaccine to immunize 70% of the world’s population, in case each person must receive two doses. However, the latest statistics of Bloomberg news show that, as of June 2, a total of more than 1.94 billion doses have been injected across 176 countries, equivalent to nearly 12.7% of the global population. required to be fully immunized. The situation of Covid-19 vaccination worldwide in terms of vaccination rate for the whole population (%). Graphics: Bloomberg In addition, there is inequality in vaccine distribution, with rich countries, which account for only 19% of the world’s population, capturing more than 50% of the full year’s supply while low- and middle-income countries, accounting for more than 50% of the total supply. More than 80% of the world’s population has access to less than a third of the vaccines shipped, exacerbating the problem. A conundrum now is how humanity can overcome the pandemic at the earliest when it is estimated that the total number of vaccines produced and distributed in the world in 2021 is only about 6 billion doses. more than 55% of the forecast demand mentioned above? Countries that have received the highest number of doses of Covid-19 vaccine in the world as of June 2. Source: Bloomberg Classification of priority groups for vaccination In order to optimize the mass vaccination campaign against SARS-CoV-2 virus in the current difficult conditions, most governments have decided to prioritize pre-vaccination for groups at high risk of infection with the virus. such as frontline medical staff, forces directly in charge of fighting the epidemic, people over 65 years old, people with chronic diseases or workers in the group providing essential services. In addition to the above approach, governments and scientists are also trying other solutions to achieve the most effective vaccination strategy possible while waiting for vaccine manufacturers to increase production and abundant supplies. more abundant. Experimental mixing of vaccines Some countries have recently considered mixing different vaccines to address shortages and delays in supply. The idea is not new, as scientists have been experimenting with this approach for decades against Ebola and HIV viruses. In the UK, scientists have decided to expand the study in the use of combinations of Covid-19 vaccines to assess whether mixing them is safe and helps prolong immunity in vaccinated people. strains or not. In February 2021, Oxford University began promoting a study called Com-Cov, whereby volunteers will be vaccinated with the first and second doses of two vaccines AstraZeneca and Pfizer/BioNTech. Preliminary research results, published in the Lancet medical journal in mid-May, revealed that mixing the two vaccines would increase the side effects of the vaccine, such as fatigue and headaches over time. short and in light form. Photo: Healthmag “It’s a finding that we didn’t anticipate. We still don’t know if this approach is associated with an improved immune response. We’ll find that out in a few weeks.” “, Professor Matthew Snape, who led the study, said on May 14. Snape and his colleagues also recently added Moderna and Novavax vaccines to the trial program. The authors hope that, if their study can demonstrate that the mixed vaccination produces an immune response as well as the standard vaccination and does not significantly increase the response to the vaccine, there will be more people complete their immunization plans sooner. This will also assist the health system in responding in the event of a shortage of any currently used vaccines. Similarly, the Philippine Department of Science and Technology (DOST) on May 24 also announced that it would start a study on mixing China’s Sinovac vaccine with other vaccines available in the country such as AstraZeneca, Pfizer/ BioNTech and Sputnik from June this year to November 2022. DOST Secretary Fortunato Dela Pena explained that Sinovac was the main target of the study because it is the most stable supply in the Philippines, accounting for 5.5 million doses out of the approximately 8.3 million doses the country has received for until now. Manila is aiming to have vaccinated more than half of its 110 million population by this year. However, according to Nikkei Asia, the nationwide vaccination campaign is facing many challenges when people focus on injecting only “branded” vaccines such as Pfizer, forcing many local governments to keep the name of the vaccine secret. Please be used in vaccinations. More spacing between injections In accordance with the regimen and recommendations of the vaccine manufacturers against Covid-19, after giving the first dose to the patient, after 3-4 weeks, medical facilities will inject the second dose (21 days apart for patients). with Pfizer vaccine and 28 days with AstraZeneca vaccine). However, the British government has decided to extend the interval between the two shots to 12 weeks to have enough vaccine to vaccinate more people. This decision caused a lot of controversy. However, British medical advisers explain, because most vaccines are proven to be more than 50% effective after the first shot, doing so will help increase immunity for more people against dangerous pathogens and help speed up the national immunization campaign. The number of new infections and deaths from Covid-19 is falling sharply in the UK. Graphics: Reuters There are no formal studies on the effectiveness of the initiative yet. However, there is an undeniable fact that the foggy country is sharply reducing the number of cases and deaths from Covid-19, allowing the country to start easing restrictive measures against the epidemic from 12/02. 4 and aims to get the country out of lockdown this summer. Vaccination for people 12 years of age and older The European Commission has approved the use of Pfizer/BioNTech’s Covid-19 vaccine for children 12 years of age and older, European Union (EU) Health Commissioner Stella Kyriakides announced on May 31. , giving the bloc’s member countries the option to expand their vaccination programmes. On the same day, the Japanese Government also announced a similar decision. The move took place not long after the US Food and Drug Administration (FDA) on May 10 approved the use of Pfizer/BioNTech vaccine for children aged 12-15. Previously, the product was only approved by the FDA. emergency use permission for persons 16 years of age and older. President Joe Biden called the FDA’s new step a promising development in the fight against the epidemic. Before the US, Canada on May 5 became the first country in the world to agree to expand the Pfizer/BioNTech vaccine recipients to children 12 years of age and older, citing more benefits. risk. However, the World Health Organization (WHO) recommends that developed countries suspend the implementation of immunization for adolescents in order to share the surplus vaccine resources with poorer countries that have a shortage of vaccination supplies for children. older, high-risk groups. “The pandemic has proven that no one is safe until everyone is safe. Equal access to a Covid-19 vaccine is within our grasp. The sooner we do it, the better. The faster our lives and our children’s lives return to normal,” emphasized Ms. Henrietta Fore, Executive Director of UNICEF.