Ask the Pharmacist

Q) My doctor has told me that she would recommend I receive the new vaccine against pneumonia. I believe I was injected with two different pneumonia vaccines a couple of years ago and was told this would be all that I would require for the rest of my life. What gives?

A) Pneumonia is so common that it often gets lumped into conversations making it sound like being diagnosed with it is comparable to catching a cold or having the flu. As many of us know by personal experience, it’s far more serious than that. About 400 per 100,000 adults require hospitalization each year due to it and about 9% of those pass away as a result of this infection. While pneumonia can affect anyone at anytime of the year there are some of us who are at a much greater risk for having a serious or even life-threatening case. These include:

· Children younger than 2
· Adults aged 65 and older
· Individuals who have been diagnosed with chronic diseases such as asthma, chronic obstructive pulmonary disease (COPD) or diabetes
· Those who are already in the hospital
· People with a weakened immune system
· Smokers

While we have antibiotics that can effectively treat most cases of pneumonia (but, given the statistics cited above, obviously not all cases) the medical community has rightly focused on preventing this infection from occurring in the first place. Given the wide breadth of this topic, we will focus on the vaccination of the adult population, which is not to imply that vaccinating our children against this infection is not just as important, if not more so.

Over the years there has been a number of different pneumonia developed. They all share some similarities but where they mainly differ and have evolved is in the number of serotypes of pneumonia bacteria that they prevent. Serotype is a medical term that refers to a distinct variation within a species of bacteria or virus. In other words, while your doctor will often diagnose your chest infection as pneumonia, there are many different types of pneumonia and they are grouped by their cause.

The two main causes are bacteria and viruses. Within just these two broad classes, there are many subtypes or serotypes. For instance, with respect to bacterial induced pneumonia the offending organism is most commonly Group A Streptococcus pneumonia but it also might be caused by Klebsiella pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, anaerobes or others. Virus that can cause pneumonia include Respiratory syncytial virus (RSV), Influenza virus, Adenovirus, Measles virus and of course Coronaviruses such as COVID-19 and SARS.

All pneumonia vaccines offer some degree of protection against a specified number of these serotypes which is indicated by their name . In recent decades, the mainstay of pneumonia vaccines has been Pneumovax 23 (PPSV23) which was first licensed in 1983 and has been routinely recommended in Ontario for adults aged 65 and older since 1996. It is part of the provincially funded vaccine program and, as such, you receive it (if you choose to get it) at the doctor’s office and it is paid for in its entirety by OHIP.

PPSV23 is made up of purified preparations of 23 different types of pneumococci thereby providing protection against all 23 of these. Eight to fifteen percent of the cases of invasive disease are caused by the serotypes found within this vaccine. The protective effects of this vaccine tend to wear off over 15 years or so.

The next major addition to our vaccine defenses was Prevnar 13 (PCV13) which was first introduced in 2009 in Europe. While Prevnar 13 offered protection against only 13 serotypes, 12 of which are also found in Pneumovax 23, there was one key serotype found only in Prevnar 13. This serotype is known as 6A. The addition of 6A enabled Prevnar 13, when combined with Pneumovax 23 (usually given about 1 year apart), to offer protection against approximately 30% of bacterial serotypes that cause invasive (i.e. more serious) cases of pneumonia.

In May of 2022, Health Canada authorized the newest addition to the pneumonia vaccines known as Prevnar 20 (PCV20). It protects against additional serotypes that are not contained within Prevnar 13 and hence offers added protection against invasive pneumonia. Both Prevnar 13 and Prevnar 20’s immune boosting effects do not seem to decline at all for the first five years after they are injected and only then do their positive effects start to slowly decline over the next decade. Evidence also suggest that both forms of Prevnar provide a greater immune response than Pneumovax 23 against most of the serotypes they have in common. Unfortunately, most adults have to pay for the either of the two Prevnar type vaccines (they run about $120 and are given as a single injection into the deltoid (just below the shoulder region) although Ontario currently will pay for Prevnar 13 for those over the age of 50 who are at risk of being hospitalized should they contract pneumonia (such as patients who received a transplant, have cancer, sickle cell disease, HIV, etc.) Note, being a senior is not enough to get OHIP to pay for this.

Sorry, that was probably way too confusing and technical for this article so let’s get to what is being recommended currently for adults.

The following guidelines apply to:

· adults over the age of 18 with an immune compromising condition
· older than 50 with risk factors (like diabetes)
· anyone 65 years of age and up

For those who have never previously received a dose of one of the older pneumonia vaccines – Receive a single dose of the new Prevnar 20.

For those who have only received Pneuovax 23 – Receive 1 dose of Prevnar 20. Make sure it has been at least a year since you were administered the Pneumovax

For those who have only received Prevnar 13 – Receive 1 dose of Prevnar 20 and make sure it’s at least 1 year after the Prevnar 13 was administered.

For the many who have already received both Pneumovax 23 and Prevnar 13 – Receive 1 dose of Prevnar 20 at least 5 years after the last pneumococcal vaccine.

So, the go to vaccine is now Prevnar 20, regardless of what other pneumonia vaccines you have had in the past. It just works that much better. You just may have to wait a little while before you can receive it. For more information about this or any other health related questions, contact your pharmacist.