The Centre for Disease Control and Prevention (CDC) has recommended a booster shot for Covid-19, following the first and second doses. In the past, vaccine programs required years of post-marketing surveillance to determine the best time interval between vaccine doses and the number of doses necessary to sustain long-term protection. However, in the case of Covid-19 pandemic, there is no luxury of time or years for such long-term protocols to observed or followed. The virus, which causes serious health complications requires  immediate and proactive approaches and  decisions to be contained… hence, the recommendation for booster shots..

So,  what is a booster shot? By definition, a booster shot is simply an extra or additional dose of a vaccine given to people following an observed  decrease in the effectiveness and efficacy of an original dose(s). A decline in the strength of protection conferred by a vaccine is often expected, especially when the causative agent mutates and has various strains or variants as in the case of Covid-19. The aim of a booster shot is to restore protection that may have waned or decreased  over a period of time to a level that is deemed insufficient to protect individuals who initially responded satisfactorily to the original vaccine doses. A booster shot is distinct from a third dose in that it is not  considered a part of the  standard primary vaccine doses. It is usually recommended on the side, when there is need to enhance immune response and establish adequate levels  of protection for individuals who have developed no or sub-optimal immune response to an original dose(s). 

A  booster, in general,  is designed to help the population retain the highest  level of immunity and for the longest possible time. Typically, individuals are encouraged to get a booster after the immunity from the initial dose(s) have naturally begun to to diminish. 

The CDC recommends a COVID-19 boosters for individuals who are 18 years or older, and have received the first and second doses. Boosters are readily available in many vaccine outlets across the world including retail pharmacies, mobile vaccination clinics and state or local vaccination sites. As with most vaccines, temporary side effects  and symptoms similar to those of a flu shot are expected for a few days. These may  include sore or swollen arm, fever, body aches, headaches, cold, general malaise and swollen lymph nodes. All Covid-19 booster shots are mRNA vaccines and can be interchangeable- either the same brand as the original doses or a different brand- the Moderna or Pfizer (mRNA) vaccine are readily available in the United States and Canada.

An additional dose- also known as a third dose, is given to people whose immune systems are moderately or severely compromised in order to improve their response to the initial doses. This is different from a booster dose in that the booster is given when a person has completed their vaccine doses, and protection against the virus has reduced over time. A third dose is especially recommended for Individuals who have cancer, underwent organ or stem cell transplant in the last two years, are taking immunosuppressive drugs, are diagnosed with HIV and have a high viral load or low CD4 count.

From all indications, COVID-19 does not seem to be backing down anytime soon; in fact, a new variant-omicron, has just been identified. Despite all precautions by individuals, organizations and governments, the pandemic has persisted. However, we must not lose hope- we must continue to follow appropriate guidelines and  recommendations  by governments and health authorities. As always, BlessWorld Foundation continues to provide information to keep the community updated about COVID-19 through her online blogs.

Stay safe and informed!

Malaria vaccine is a long awaited,  ground breaking invention and breakthrough in medical science.. Since time immemorial, malaria has persisted in sub-Saharan Africa, causing significant health challenges, personal suffering, loss of life and economic drawbacks. The continent, and world at large,  has long hoped and looked forward to the birth of an effective malaria vaccine. Now, for the first time ever, the dreams of many have come true- a malaria vaccine recommended for widespread use has been approved by World Health Organization (WHO). This great progress increases the hope that someday, the menace and misfortune caused by malaria, mostly in Africa- the continent with the heaviest burden of malaria, and other continents, will be history.

Based on the results of  an ongoing pilot program from 2019 in Ghana, Kenya and Malawi, WHO has  recommended a widespread use of the RTS,S/AS01 (RTS,S) malaria vaccine- schedule of 4 doses in children from 5 months of age, in sub-Saharan Africa and in other regions. These regions are considered to have moderate to high Plasmodium falciparum malaria transmission.. The program has currently reached over 800,000 children since it’s onset in  2019. It is projected that the vaccine, in addition to other existing malaria prevention tools, could save tens of thousands of lives annually.

Clearly, the benefits of inventing and administering the malaria vaccine are extensive given that malaria is the primary cause of childhood illness and death in sub-Saharan Africa. Approximately, two hundred and sixty thousand (260,000) African children below five years of age die yearly from malaria. Findings from the pilot program mentioned above have continued to inform WHO’s decisions regarding the malaria vaccine. Established facts and benefits of the vaccine include:

• Feasibility: The malaria vaccine administration is very feasible as it follows  four scheduled doses
• Accessibility: Vaccines are funded by international organizations and are available in countries where malaria cases and  incidents are high
• Positive and strong safety profile: The vaccine has not been associated with any side effect and is considered safe.
• Cost effectiveness: Given the economic impact of malaria, vaccination which reduces the incident of malaria is a cost-effective practice
• Significant reduction in number of cases: Up to 30% reduction in the number of malaria cases have been recorded in some countries and regions where the vaccine has been introduced

According to CDC, malaria is a critical, potentially  fatal disease caused by the parasite,  Plasmodium falciparum- which feeds on human blood. Symptoms of malaria are typically similar to the  flu with high fevers, chills, and  headache. Although there are other plasmodium species that cause malaria, P. falciparum causes symptoms that may most likely result in severe cases and possibly death,  if not promptly treated. Generally, illness and death from malaria can usually be prevented.

About 2,000 malaria cases are diagnosed in the United States annually, majority which are travellers and immigrants returning from parts of the world where malaria transmission occurs, particularly sub-Saharan Africa and South Asia. Worldwide, millions of malaria cases occur clinically causing hundreds of thousands of deaths. Malaria transmission occurs when people are bitten by infective female Anopheles mosquitoes- the only mosquitoes that transmit malaria, and they must have been infected by a P. falciparum through a previous blood meal  from an infected person. Malaria can also be transmitted through blood transfusion, organ transplant or the shared use of needles or syringes contaminated with blood because  the malaria parasite is found in red blood cells of an infected person. Malaria may also be transmitted from a mother to her unborn infant before or during delivery, known as congenital malaria. Malaria is not spread from person to person, and it cannot be sexually transmitted.

Scientists have been working hard to find a vaccine for malaria, however, a completely effective vaccine is not yet available. Currently, there are  several vaccines under development- these vaccine candidates target the blood-stage of the parasite’s life cycle but  that has not been sufficient. Consequently, several potential vaccines targeting the pre-erythrocytic stage are being developed.

So far, R21/Matrix-M, with 77% efficacy shown in clinical trials is the most effective malaria vaccine. It meets the World Health Organization’s goal of a malaria vaccine with a requirement of at least 75% efficacy. The vaccine was developed following a collaboration of various institutions including Oxford University, Kenya Medical Research Institute, London Hygiene and Tropical Medicine, Serum Institute of India amongst others. Further clinical trials are needed to approve the vaccine, which has an expected annual production of 200million doses.

More so, RTS,S- developed by PATH Malaria Vaccine Initiative  (MVP) and  GlaxoSmithKline (GSK),  and supported by  Bill and Melinda Gates Foundation is a recent  recombinant vaccine which comprises of the P. falciparum  circumsporozoite protein (CSP) from the pre-erythrocytic stage. The CSP antigen stimulates the production of antibodies capable of preventing the infection of blood cells as well as destroying already infected cells. The vaccine is commercially traded as Mosquirix, and requires four injections.

In July of 2015, Mosquirix was positively appraised by the European Medicines Agency (EMA) on the proposal for the vaccine to be used in children aged 6 weeks to 17 months outside the European Union. Subsequently, a pilot project for vaccination was launched in 2019 for children in Malawi, Ghana and Kenya. The vaccine was then endorsed by the World Health Organization in October 2021.