- Two articles have recently appeared that update the epidemiological situation of invasive pneumococcal disease (IPD) in our country.
- Although the methodology is different, both studies yield, with some differences, similar results.
- Both studies show that up to 60-70% of IPD cases are currently caused by serotypes not contained in the 13-valent pneumococcal conjugate vaccine.
- A relevant finding is that a substantial proportion of IPD is caused by vaccine serotypes included in PCV13.
- The 10 most frequent serotypes in Spain that cause IPD and the distribution of the serotypes in children under 5 years of age are presented.
- 50% of the serotypes that cause IPD are not covered by either PCV15 or PCV20, so monitoring will be essential to evaluate the possible impact of the extended-valence pneumococcal vaccines that will arrive in the coming years.
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Introduction
Recently, two articles have appeared, the first of National Center of Epidemiology (CNE) and the second of National Pneumococcus Reference Laboratorywhich update the situation of the epidemiology of invasive pneumococcal disease (IPD) in our country. Although the methodology is different, both studies yield, with some differences, similar results.
One finding, already anticipated, is that after the pause of the COVID-19 pandemic, in which pneumococcal infections (and other respiratory transmitted bacterial infections) decreased – largely due to the absence of circulation of respiratory viruses due to to confinement measures – the incidence and number of pre-pandemic cases have been reached and even exceeded, especially in children under 4 years of age (1), as has happened in other countries.
Also, and as expected, both studies show that up to 60-70% of IPD cases are currently caused by serotypes not contained in the 13-valent pneumococcal conjugate vaccine (non-vaccine serotypes or SNV), common phenomenon with most countries in which this vaccine has been used. However, a relevant finding is that a substantial proportion of IPD is caused by vaccine serotypes (VS) included in PCV13: 3, 19A, 19F, 14 and 4 (1,2). This persistence of VS has been confirmed in many European countries with high vaccination coverage (3-5).
Most prevalent serotypes causing IPD in Spain
Figure 1 shows the 10 most frequent serotypes causing IPD in both studies and at all ages with similar results: the first three are 8, 3 and 22F. The striking increase in serotype 3 after the pandemic has also occurred in other countries, until it became the first cause of IPD (4,5).
Figure 1. The 10 most frequent serotypes causing Invasive Pneumococcal Disease in Spaina.
In children under 5 years of age, the distribution of serotypes causing IPD is different (Figure 2). In both studies, the most common serotype is 3, followed by serotypes 24F and 22F. Serotype 8 is much less prevalent in children than in adults, and it mainly affects older children (1).
Figure 2. Distribution of serotypes causing Invasive Pneumococcal Disease in Spain in children under 5 years of age.
The 24F serotype, essentially pediatric, has remained constant over the last 3 years and predominantly affects children under 4 years of age. It tends to cause meningitis and frequently associates resistance to antibiotics (4,6). In France, it experienced a rapid increase after the introduction of PCV13, which counteracted the decrease in cases of meningitis due to other serotypes (6).
In people over 65 years of age, serotype 3 is the most common. Given the high lethality of pneumococcal infections in this age group (1,7,8), it is not surprising that, in 2023, 75% of deaths from IPD were due to this serotype in our country (1). In Portugal, after the pandemic, serotype 3 has also been the most frequent cause of IPD followed by serotypes 8, 10A and 24 F (4).
Reasons for the persistence of vaccine serotypes
The reasons for the persistence of SVs are not completely known. VNC13 is effective against IPD due to serotype 3 (9), although its effectiveness is less than that against other serotypes. This may be the reason why serotype 3, along with 19A and 19F, are the most frequent in vaccine failures (1,10). It is a proven fact that protection against IPD by these three serotypes requires higher levels of antipolysaccharide antibodies (11), which is probably related to a more rapid loss of effectiveness of PCV13 against serotypes 3 and 19A (3).
Perhaps the fact that best explains the poor impact of PCV13 on IPD caused by serotype 3 is its little or no effect on nasopharyngeal colonization by this serotype. In England, after 10 years of vaccination with PCV13, the only SVs that persist in the nasopharynx are 3 and 19A (12). The same happens in a country as close to ours as Portugal, where the most common vaccine serotypes are 19F, 3 and 19A (13). In this same country, the most frequent SNVs in the nasopharynx are: 15B/C, 11A, 23A, and 23B (13).
Most prominent non-vaccine serotypes causing IPD
Among the non-vaccine serotypes (SNV), serotypes 4, 10A and 11A deserve some comment.
Serotype 4 affects almost exclusively adults (1) and its increase has been observed in other countries, such as England (5). Serotype 10A, whose presence seems to be increasing, mainly affects children under 4 years of age, has a high invasive capacity and tends to cause meningitis (4). Serotype 11A is associated with resistance to penicillin and amoxicillin (14,15) and is, of all pneumococcal serotypes, the most lethal (1,7).
In conclusion
Data from both studies provide detailed estimates of the potential coverage of PCV15 and PCV20 vaccines in different age ranges. Thus, while in adults the percentage of coverage for VNC15 and VNC20 ranges around 40% and 75%, respectively, in children under 5 years of age this difference is smaller (around 45-50% for VNC15 and 60-70% for NCV20).
50% of the serotypes that cause IPD are not covered by either VNC15 or VNC20, so monitoring IPD will be essential to evaluate the possible impact of the expanded valence VNCs that will arrive in the coming years.
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Literature
1. Soler-Soneira M, Del-Águila-Mejía J, Acosta-Gutiérrez M, Sastre-García M, Amillategui-Dos-Santos R, Cano Portero R. Invasive Pneumococcal Disease in Spain in 2023. Weekly Epidemiological Bulletin. 2024;32(2):74-93.
More information on this website
– CAV-AEP. Pneumococcus, in the AEP online Immunization Manual.
– CAV-AEP. Other news about pneumococcus and its vaccination.
Oh Look, Pneumococcal Disease Is Back! (And It’s Throwing a Party)
Welcome, dear readers, to today’s dose of delightful doom and gloom! We’re diving into the wonderful world of invasive pneumococcal disease (IPD). Yes, it’s back! And surprise! It appears to be bringing more uninvited guests than ever—serotypes that our beloved vaccines aren’t ready to tackle. It’s like a bad wedding where more people RSVP’d than you anticipated, and none of them brought a gift!
In a Nutshell
- Two articles are out, updating us on the latest pneumonia drama in our country.
- Both studies—different methodologies, similar results. Think of them as the “Batman vs. Superman” of epidemiology!
- 60-70% of IPD cases now come from serotypes not in the 13-valent pneumococcal conjugate vaccine (PCV13). That’s like finding out your favorite restaurant has gone vegan—lots of options, just not the ones you like!
- And while we’re at it, don’t forget: a fair number of IPD cases still come from vaccine serotypes in PCV13. It’s like that one friend who is always late but still shows up.
- The top 10 mischief-makers of IPD in Spain and the breakdown for children under 5 are hot off the press!
- But here’s the catch: 50% of the culprits are not covered by the shiny new vaccines (PCV15 or PCV20)—so grab your popcorn; the sequel is on its way!
Introduction: The Plot Thickens
So, we have two studies (yes, two, because one clearly wasn’t enough). They come from the National Center of Epidemiology and the National Pneumococcus Reference Laboratory. They both scream “IPD is back!” but with slightly different accents due to their different methodologies. A real Shakespearean drama, minus the tragic death count.
After a pandemic pause that made the world a quieter, more germ-free place, guess what? IPD has gone right back to being a nuisance, especially in pint-sized individuals under 4. They really have a knack for needing attention, don’t they?
Who’s Who in the IPD Zoo?
Let’s get to the interesting bit. The first three notorious serotypes shaking up Spain’s IPD scene are:
- Serotype 8
- Serotype 3
- Serotype 22F
And who would have thought that serotype 3 would take the crown? It’s like the IPD royal family had a coup, and serotype 3 is the new king. Just look at other countries—it’s a global phenomenon. The IPD world is turning into a reality TV show, and we can’t change the channel!
Reasons Why Some Serotypes Just Won’t Get the Hint
Why are serotypes like serotype 3 such loyal party crashers? Well, it turns out that the 13-valent vaccine does have some kick, but it’s clearly less effective against serotype 3. It’s like trying to use your phone to call the police while you’ve lost your signal. Good luck!
The Non-Vaccine Serotype Drama
Now let’s talk about serotypes not invited to the vaccine party. They’re cheeky little things—like serotype 4, which plays exclusively with adults. You know, the “serious” crowd. Serotype 10A is making waves mainly among the under-4 crew, creating all sorts of headaches (literally). And let’s not ignore the intimidating serotype 11A—it’s the lethal one of the group, and boy, does it play rough!
Conclusion: The Sequel Is Coming!
Based on both studies, it seems we need to keep an eye on these sneaky serotypes. The potential vaccine coverage is teetering around 40-75%, depending on the group. And while a good portion of kids might be covered, 50% of the culprits are still looking for a ticket into the pandemic’s VIP section with no vaccine to stop them.
So what do we do? Grab your binoculars, my friends; we’re entering a new world of monitoring IPD with the soon-to-arrive vaccines. Make sure you’re ready for whatever surprises these sneaky serotypes have in store! After all, nothing says ‘pneumonia’ quite like cranky kids and grown-ups sneezing!
References
Research conducted by:
Soler-Soneira M et al. (2024). “Invasive Pneumococcal Disease in Spain in 2023.” Weekly Epidemiological Bulletin, 32(2):74-93.
How do vaccination efforts impact the prevalence of non-vaccine serotypes like 4 and 10A in invasive pneumococcal disease?
Oes provide some protection against it, but not as much as against other serotypes. Think of it as giving a half-hearted invitation to a guest—you were hoping they wouldn’t show up, but here they are, right at your door! The persistence of serotype 3 is particularly problematic because it requires higher levels of neutralizing antibodies for effective protection, which the current vaccines like PCV13 aren’t adequately providing.
Moreover, these pesky serotypes are pretty good at establishing themselves in the nasopharynx, essentially setting up camp and refusing to leave. In places like England and Portugal, serotypes such as 3 and 19A have managed to remain dominant even after years of vaccination efforts. It’s like they’re saying, “Thanks for the invite, but we’ll take a seat, thanks.” This indicates that vaccination strategies may need a rethink; perhaps we need to be more strategic about how we design our immunity campaigns to target these invasive and stubborn strains.
### The Non-Vaccine Serotypical Rebels
Now, let’s talk about the non-vaccine serotypes that are adding their own twist to this ongoing saga of IPD. Serotype 4, for instance, has started to show up primarily in adults and appears to be increasing in prevalence. It’s like the older generation of serotypes have decided to come back into fashion! On the other hand, serotype 10A is making a name for itself among children under 4 and has a notorious reputation for causing invasive diseases like meningitis. And who could forget the lethal serotype 11A that is raising eyebrows for its resistance to penicillin and amoxicillin? It stands as a chilling reminder that the IPD landscape is changing, and not for the better.
### Conclusion: The IPD Future Awaits
despite the exciting prospects of advancements in vaccines like PCV15 and PCV20, they still leave a substantial chunk of the responsibility on our shoulders. With approximately 50% of serotypes responsible for IPD not covered by these vaccines, this is a call to action for constant monitoring and adaptation of our public health strategies. As we navigate through this unpredictable territory, we’ll need to be vigilant and innovative to keep our communities safe from the lurking threats of invasive pneumococcal disease. So, grab your popcorn indeed—we’re all in for some riveting public health drama ahead!
