Pneumococcal 21-Valent Conjugate Vaccine: A Comprehensive Overview

Overview:

Pneumococcal 21-valent conjugate vaccine is a bacterial vaccine that you will get as an injection into your muscle. If you are 18 or older, this vaccine is designed to protect you from pneumonia, which is when one or both of your lungs get infected, and the air sacs become inflamed. The leading cause includes various strains of Streptococcus pneumoniae and Gram-positive bacteria.

The FDA (Food and Drug Administration) approved this vaccine for adults 18 and older in June 2024. It works by helping your body build its own defenses against pneumonia through active immunization.

In this article, you will learn everything you need to know about this vaccine: when you should get it, when you should not, what side effects you might experience, how it works in your body, essential safety warnings, and what medications it might interact with.

Dose Form and Strength Availability

• Injection (Intramuscular): A single-dose vial of 0.5 mL (milliliters).

For Patients:

Why Is the Pneumococcal 21-Valent Conjugate Vaccine Prescribed?

Indications of Pneumococcal 21-Valent Conjugate Vaccine:

• If you are 18 or older, this vaccine can help protect you from pneumonia caused by specific types of Streptococcus pneumoniae bacteria. It works against serotypes 3, 6A, 7F, 8, 9N, 10A, 11A, 12F, 15A, 15C, 16F, 17F, 19A, 20A, 22F, 23A, 23B, 24F, 31, 33F, and 35B by helping your body build its own defense system.

• You will also get protection from invasive disease caused by Streptococcus pneumoniae. The vaccine covers serotypes 3, 6A, 7F, 8, 9N, 10A, 11A, 12F, 15A, 15B, 15C, 16F, 17F, 19A, 20A, 22F, 23A, 23B, 24F, 31, 33F, and 35B. It is designed to help your immune system recognize and fight off these bacteria if you ever come into contact with them.

How Should the Pneumococcal 21-Valent Conjugate Vaccine Be Used?

When you are using these vaccines, you will want to use them straight from the vial without mixing them with anything else or watering them down. Ensure you administer the full recommended dose all at once.

If you are giving someone the Pneumococcal 21-valent conjugate vaccine along with another vaccine at the same time, you need to use different spots on their body for each injection. This helps prevent any unwanted interactions between the vaccines.

Before administering the vaccine, take a close look at it. Check for any particulate matter or discoloration; if you see anything like that, do not use it. What you are looking for is a clear solution that might look slightly milky but should be colorless.

The prefilled syringes are meant for one person only. Once you have used it on someone, that's it; you cannot use the same syringe on another patient.

What Precautions Should Be Taken Before Using the Pneumococcal 21-Valent Conjugate Vaccine?

• This vaccine needs to go into your muscle (IM or intramuscular); that is the only way it works properly. If you are allergic to the Pneumococcal 21-valent conjugate vaccine, any of its ingredients, or really any other medication, you will want to let your doctor know right away.

• If you are pregnant, breastfeeding, or thinking about having a baby, or maybe you find out you are pregnant while getting this vaccine, you should tell your doctor about it.

• Your doctor should be aware of all medications you are currently taking or plan to take, including prescription, over-the-counter, herbal supplements, vitamins, and nutritional products. It all matters.

• If you have had any medical issues in the past, especially bleeding problems (like thrombocytopenia), make sure to mention that before getting your shot.

What Are the Side Effects of the Pneumococcal 21-Valent Conjugate Vaccine?

The pneumococcal vaccine side effects are as follows:

Common Side Effects:

• Headache.

• Fever.

• Muscle aches.

• Fatigue.

• Injection site pain, swelling, and redness.

Serious Side Effects:

• Hives.

• Troubled breathing.

• Wheezing.

• Rash.

• Swelling on the lips, tongue, or face.

Missed Dose:

You will only get this vaccine once. Since it is just a single shot, you do not have to worry about forgetting a dose or keeping track of a schedule.

Overdose:

If you suspect you have received too much vaccine, you will want to call the emergency department right away. But if things start looking serious or you are feeling really unwell, don't wait; get emergency medical help immediately. They will know exactly how to monitor and treat you.

Storage and Disposal:

Your doctor will store this vaccine in the refrigerator between 36 and 46° Fahrenheit (that is, 2 to 8° Celsius). They will keep it away from direct sunlight and any moisture. Just so you know, they won't freeze it, and the vial cap and plunger are not made from natural rubber latex, which is great if you have latex concerns.

When it comes to getting rid of unused vaccine or any waste, your healthcare team handles all of that. They follow local disposal rules or FDA guidelines to make sure everything is disposed of safely and properly. You do not need to worry about this part; they have got it covered.

For Doctors:

What Is the Clinical Pharmacology of the Pneumococcal 21-Valent Conjugate Vaccine?

Mechanism of Action of Pneumococcal 21-Valent Conjugate Vaccine

Once you have gotten your Pneumococcal vaccine, how can we check if it is working for you?

We use something called an OPA test (that is, the opsonophagocytosis assay) to see if your body is making the right antibodies. These antibodies basically tag the pneumococcal bacteria so your immune cells can spot them, gobble them up, and destroy them. OPA responses are important; they are like a sneak peek at how well the vaccine will protect you from pneumococcal diseases.

Now, we don't have exact numbers yet for what counts as "good protection" in adults, but when your OPA responses go up, so do your anti-capsular IgG (immunoglobulin G) antibodies. They work together like a team.

This vaccine is packed with immune-boosting ingredients for 21 different types of pneumococcus bacteria. We can measure your body's response to each type, plus two bonus ones (15B and 6C) that cross-react with others. We use special tests called validated multiplexed OPA (MOPA) and Pn ECL (pneumococcal electrochemiluminescence) to check these. There is also serotype 15C, which shows us how you are responding to deOAc15 B. They are basically molecular twins, so we can use one to understand the other.

While this vaccine does an excellent job of protecting most people, it may not be entirely effective for everyone.

Clinical Studies:

Concomitant Vaccination

In a double-blind study, around 1,080 individuals aged 50 years and older, with or without a history of Pneumococcal vaccination, were randomized in a 1:1 ratio. Vaccination group one (concomitant group) received the Pneumococcal 21-valent conjugate vaccine and QIV (quadrivalent influenza vaccine) concomitantly, followed by a placebo 30 days later. A second vaccination group (sequential group) received a placebo and QIV concomitantly, followed by a Pneumococcal 21-valent conjugate vaccine 30 days later. Post-vaccination, after approximately one month, antibody responses were assessed.

The OPA responses were non-inferior for the Pneumococcal 21-valent conjugate vaccine administered concomitantly with QIV as compared to the OPA responses to the Pneumococcal 21-valent conjugate vaccine administered sequentially after QIV for 20 of 21 serotypes [lower bound of the two-sided 95 percent CI (confidence interval) of the GMT (geometric mean tires) ratio (concomitant group/sequential group) was greater than 0.5]; the non-inferiority was not met for serotype 23B [the lower bound of the two-sided 95 percent CI (confidence interval) of the GMT ratio (concomitant group/sequential group) was 0.44]. On the other hand, the OPA response to serotype 15B was not assessed for non-inferiority. Moreover, in a descriptive analysis, the OPA GMT in the concomitant group was 3,438.7, and in the sequential group, it was 4,440.5, with a geometric mean tire ratio of 0.77 (95 percent CI: 0.64, 0.94). The influenza strain-specific hemagglutination inhibition (HAI) responses to the quadrivalent influenza vaccine administered concomitantly with the Pneumococcal 21-valent conjugate vaccine were non-inferior to the HAI responses to the quadrivalent influenza vaccine administered alone for three of four influenza strains [the lower bound of the two-sided 95 percent confidence interval for HAI GMT ratios (concomitant group/sequential group) was greater than 0.67 (non-inferiority margin); the lower bound was 0.67 for the A/H3N2 influenza strain].

Immunogenicity: Cross-Reactive Immune Responses to the Pneumococcal 21-Valent Conjugate Vaccine

The Pneumococcal 21-valent conjugate vaccine elicited an immune response to serotype 15B, a cross-reactive to serotype 15C, and serotype 6C, a cross-reactive to serotype 6A. In a 003 study, in individuals 50 years of age and older, the Pneumococcal 21-valent conjugate vaccine met the predefined criterion (lower bound of the two-sided 95 percent CI of the proportion of individuals with a Pneumococcal 21-valent conjugate vaccine greater than or equal to a four-fold rise in OPA responses is greater than 50 percent) for antibody response to serotype 15B, with a lower bound of the two-sided 95 percent CI being 61.4 percent; the antibody response did not meet the criterion for serotype 6C, with the lower bound of the two-sided 95 percent CI being 46 percent versus 50 percent the Pneumococcal 21-valent conjugate vaccine successfully immuno-bridged serotype-specific immune response for serotype 15B in individuals aged 18 to 49 years to individuals aged 50 to 64 years of age, as the lower bound of the two-sided 95 percent CI for the GMT ratio was greater than 0.5. For the immune response to serotype 6C in individuals aged 18 to 49 years compared to those aged 50 to 64 years, the GMT ratio observed was 2.05 (95% CI: 1.52, 2.77).

In Protocol 004 of the double-blind study, pneumococcal vaccine-naïve adults aged 18 to 49 years were randomized in a 1:1:1:1 ratio to receive one of four lots of the Pneumococcal 21-valent conjugate vaccine. The study demonstrated that for all 21 serotypes, all three lots were equivalent, as the lower and upper limits of the two-sided 95 percent CI of the serotype-specific OPA GMT ratios between any two lots were within the equivalence margin (0.5 to 2.0). Following vaccination, immune responses with the Pneumococcal 21-valent conjugate vaccine were comparable for the 12 common serotypes and higher for nine unique serotypes.

Ingredients:

Active Ingredients: Streptococcus pneumoniae serotypes 1, 3, 4, 5, 6B, 7F, 9V, 14, 18C, 19A, 19F, 22F, 23F, and 33F.

Inactive Ingredients: Polysorbate 20, histidine, water, sodium chloride.

Dosing and Administration:

You will get this medication as a shot in your muscle (IM), and that is the only way it is given.

If you are 18 or older, you will receive just one dose of 0.5 mL.

Note: Have you had a different pneumococcal vaccine before? If so, you will need to wait at least a full year from your last shot before getting this 21-valent conjugate vaccine. Your body needs that time between doses to respond properly.

What Are the Contraindications of the Pneumococcal 21-Valent Conjugate Vaccine?

You should not get the Pneumococcal 21-valent conjugate vaccine if you have had any allergic reactions to it before. This includes being sensitive to any of its ingredients or to diphtheria toxoid. If you have experienced hypersensitivity to these components in the past, this vaccine is not right for you.

What Are the Warnings and Precautions for the Pneumococcal 21-Valent Conjugate Vaccine?

• Allergic Reactions (Including Severe Ones): Just so you know, this vaccine could trigger allergic reactions, and sometimes they can be serious. That is why your healthcare team will want to keep a close eye on you after you get the shot. You will need to stick around for at least 30 minutes after your vaccination so they can make sure you are doing okay.

• If Your Immune System Is Weakened: Are you taking medications that suppress your immune system, or do you have a condition that affects your immunity? If so, you should know that your body might not respond as strongly to this Pneumococcal 21-valent vaccine as someone with a healthy immune system would.

• If You Have Bleeding Issues: Do you have any bleeding disorders, like low platelet counts? If that is the case, your healthcare provider needs to be extra cautious when administering this vaccine to you. Since it is given as a shot into the muscle, there is a chance you could have some bleeding at the injection site.

What Are the Drug Interactions and Precautions for the Pneumococcal 21-Valent Conjugate Vaccine?

• Acetaminophen.

• Azathioprine.

• Cyclosporine.

• Hydroxyurea.

• Imiquimod.

• Fingolimod.

• Glatiramer.

• Tacrolimus.

• Mycophenolate.

• Tofacitinib.

• Warfarin.

• Corticosteroids (such as Budesonide, Dexamethasone, Hydrocortisone, Fluticasone, Prednisone).

• Immunosuppressive therapy (such as some medications used for treating cancer, transplant recipients, or immune conditions).

• Medications to treat cancer (such as Carboplatin, Cyclophosphamide, Doxorubicin, Ifosfamide, and Vincristine).

• Monoclonal antibodies (Belimumab, Eculizumab, Golimumab, Infliximab).

• Other vaccines.

Uses In Specific Populations

Pregnancy

If you are pregnant, read ahead. Studies on animals have not shown any harmful effects on developing babies. While every medication carries some risk during pregnancy and might cause unwanted effects, we do not have enough information yet about how safe or effective the Pneumococcal 21-valent conjugate vaccine is for pregnant women.

Breastfeeding

If you are breastfeeding, we do not have clinical data showing whether this vaccine affects your milk production or your baby. We also do not know if it passes into breast milk or how safe it is for nursing mothers. That is why your doctor needs to weigh several factors before recommending this vaccine, like the potential benefits for your health, your current medical needs, and any possible effects on your breastfed baby.

Pediatric Use

For kids under 18, we have not established whether this vaccine is safe or effective yet.

Geriatric Use

Good news: if you're 65 or older, the vaccine works similarly for you as it does for younger adults. Whether you are 68 to 75 or over 75, your body's response to the vaccine and its safety profile are comparable to those under 65.

A Key Takeaway:

• The pneumococcal 21-valent conjugate vaccine is a US-approved medicine. Adults can take this to protect themselves from pneumonia and meningitis.

• This vaccine covers serotypes for 85 percent of pneumococcal disease cases in adults aged 65 and older.