Pneumococcal infection is a leading cause of morbidity and mortality in children around the world. The prevalence of Streptococcus pneumoniae (pneumococcus) infection varies with age and geographic location, yet it is still a significant worldwide health burden. Pneumococcal infections are predicted to grow more serious as the world’s population ages. Pneumococcal pneumonia can have both short-term and long-term morbid effects, even with proper treatment. As a result, prevention has become a significant issue. The development of pneumococcal vaccines has advanced significantly over the past century, even though immunization should still be the cornerstone of our current approaches to combating this infection. There is still work being done to create a vaccination that will remain effective against the majority of pneumococcal serotypes, despite the fact that new pneumococcal conjugate vaccines give promise for the prevention of pneumococcal infections. Consequently, despite breakthroughs in pneumococcal immunization, the worldwide burden of pneumococcal illness remains substantial. This article aims to cover the most recent developments in PCV vaccines and how they work to keep us safe.
Early Years of Pneumococcal Vaccine
More than a century ago, the South African gold mining business invited British physician Almroth Wright, who had previously worked on a typhoid fever vaccine, to examine pneumococcal vaccination in men working in Witwatersrand gold mines. Following the inoculation of various doses of dead pneumococci, Wright and his colleagues’ investigations revealed a significant decrease in pneumonia cases as well as in fatalities. And there was the start of the pneumococcal vaccine. This process carried on until it eventually led to the various types of PCV vaccinations. Even before the discovery that different pneumococci were antigenically diverse, the experiment demonstrated that immunization with killed pneumococci was efficacious. The development of type-specific vaccinations using entire dead pneumococci demonstrated high efficacy. The period of capsular polysaccharide vaccination began with the recognition of the significance of the pneumococcal capsule, but as penicillin became more widely used, interest in the creation of pneumococcal vaccines began to fade.
The Advent of PCVs
The work of a scientist named Robert Austrian and his colleagues, who proved that despite penicillin therapy, patients died from pneumococcal infection within the first 96 hours, eventually led to the approval of a 14-valent pneumococcal polysaccharide in 1977, followed by a 23-valent pneumococcal polysaccharide in 1983. The main issue with them, as with other polysaccharide vaccines, was that they did not effectively protect newborns and young children, who posed the greatest risk for pneumococcal illness. By chemically coupling the polysaccharide molecules to an immunogenic carrier protein, this problem was solved. Hence came the age of pneumococcal conjugate vaccination (PCV), which began with PCV7 and progressed to PCV10 and PCV13, and, more recently, PCV15 and PCV20.
First Types of PCVs
Older pneumococcal conjugate vaccines, PCV 7 and PCV 10, were granted FDA approval in 2000 and 2010, respectively. They are no longer administered in the U.S. but may still be used in other nations. They provide protection against 7 and 10 different kinds of pneumococcal bacteria. Because they offer less protection than the more recent PCVs against different strains of pneumococcal bacteria, PCV 10 and PCV 7 are no longer in use. Moreover, PCV 10’s efficacy against serotype 19A IPD in the youngest age groups has not been established. On the other hand, PCV13 is effective at preventing invasive pneumococcal disease (IPD) caused by the vaccine’s 13 serotypes. Nevertheless, PCV13 is ineffective against serotype 3, which is a common cause of IPD and pneumonia. The effectiveness of PCV13 varies according to the age group, the number of doses administered, and the recipients’ underlying medical conditions.
The Superiority of PCV15 and PCV20
The most recent advances in PCV vaccines are PCV15 and PCV20, which are considered third-generation PCV vaccines.
PCV15
One of the third-generation PCVs, PCV15, produced by Merck Vaccines, consists of the 13 pneumococcal serotypes present in PCV13 (1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23F) together with the additional serotypes 22F and 33F, which are associated with infection caused by antibiotic-resistant strains of the pneumococcus as well as with severe disease, including pneumonia, meningitis, or sepsis. The U.S. Food and Drug Administration (FDA) granted PCV15 approval on June 22, 2022, for infants and children and on July 16, 2021, for individuals who are 18 years of age and older. It is also known as VAXNEUVANCETM12. Pneumococcal illness is brought on by bacteria that can infect the blood, brain, or lungs. PCV15 is a vaccination that aids in protecting against this condition. PCV15 protects against 15 different kinds of pneumococcal bacteria that cause the majority of invasive pneumococcal illnesses. It functions by encouraging the production of antibodies in your body that, if exposed to certain bacteria, will enable you to fight them off.
PCV20
PCV20 is a pneumococcal bacterium vaccination that protects against 20 different varieties of pneumococcal bacteria that can cause serious diseases such as pneumonia, meningitis, and blood infections. It was approved in 2021 for those aged 18 and up and is recommended by the CDC as a choice for adult pneumococcal disease prevention. In addition to the capsular polysaccharides found in PCV13, which are derived from serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23F, PCV20 contains seven novel serotypes: 8, 10A, 11A, 12F, 15 B/C, 22F, and 33F. The addition of the new serotypes provides additional protection against deadly diseases (8, 10A, 11A, 15B/C, 22F, and 33F), pathogen infection with antibiotic-resistant strains (11A, 15B/C, 22F, and 33F), and meningitis (10A, 15B/C, 22F, and 33F). PCV20, according to some studies, is safe and well-tolerated, with immunogenicity equivalent to other pneumococcal vaccines. Depending on the person’s age and medical history, it can be given as a single dose or in combination with another pneumococcal vaccination.
Other Recent PCV Vaccine Advances
Because of the numerous advantages of each PCV vaccination, it has been extensively approved and employed in nations all over the world. For instance, they can stop many cases of AOM (acute otitis media) and IPD (invasive pneumococcal disease) in kids. They can also help to minimize antibiotic resistance by reducing antibiotic use for pneumococcal infections. They can protect those who are more vulnerable to pneumococcal infections, such as those with chronic conditions or weakened immunity. On the other hand, unfortunately, in some areas or nations, they could not be accessible or economical. The fact that these vaccines, which are widely available in the majority of affluent countries, are somewhat expensive in developing nations should be noted as one of their disadvantages. Thankfully, one of the most significant recent advancements in the field of PVC vaccines has been the introduction of related biosimilar vaccinations, which offer all the benefits of biologic vaccines while also being relatively reasonably priced, allowing more people and nations access to them. The most widely used and sought-after PCV vaccinations are now being produced as biosimilars by OBP, enabling developing countries to benefit from this advanced medical technology.
Conclusion
One of the most significant developments in vaccine technology is the development of PCV vaccinations. The pneumococcal vaccine has gone a long way in recent years and now provides a safe, effective, and important tool for protecting ourselves from life-threatening illnesses such as pneumonia, meningitis and other diseases. Research has concentrated on microbiology, epidemiology, pathology, and the creation of efficient vaccination techniques to guard against pneumococcal infection since pneumococcus was discovered in 1881. The earliest vaccinations relied on the inoculation of mixed pneumococcus serotypes that had been heat-killed. Since then, though, scientists have looked into many vaccine strategies. The most recent improvements to PCV vaccinations have increased their efficacy and improved their ability to protect against a variety of diseases. PCV vaccines aid in the development of antibodies and the prevention of invasive pneumococcal illness. In order to keep you and your family safe and healthy, getting vaccinated is the best option. This blog post covered the most recent developments in PCV vaccines and how they can help protect you from life-threatening infections. That’s why the most recent developments in PCV vaccines were covered in this blog post.
