If you’re shipping to basic training, expect roughly seven to ten injections in the first few days, plus one long-acting antibiotic shot in the backside. The shots you get in basic training are the same across the Army, Navy, Air Force, Marine Corps, and Coast Guard because a single joint service regulation governs all branches. The core lineup covers adenovirus, seasonal flu, meningococcal, MMR, Tdap, and varicella up front, with hepatitis A, hepatitis B, and polio added later in training or at your first duty station.1U.S. Air Force. AR 40-562 Immunizations and Chemoprophylaxis for the Prevention of Infectious Diseases
The First Round of Shots
The first cluster hits before or at the start of collective training. It targets the diseases most likely to sweep through a barracks full of people from all over the country breathing the same air.
- Adenovirus (types 4 and 7), a leading cause of respiratory illness in training environments
- Influenza, the seasonal flu shot
- Meningococcal, which protects against bacterial meningitis
- MMR, for measles, mumps, and rubella
- Tdap, for tetanus, diphtheria, and pertussis
- Varicella (chickenpox), if you lack documented immunity
Pneumococcal vaccine can be added if local health conditions call for it, but it isn’t standard for every recruit.
The flu shot is worth calling out on its own. It’s the only vaccine the Department of Defense explicitly mandates on an annual basis for every active-duty service member, and individual compliance is tracked through the Medical Readiness Reporting System.2Department of Defense. DoDI 6205.02 DoD Immunization Program
The Second Round Later in Training
The remaining vaccines come later in training or once you reach your first duty station. They cover broader risks tied to military service and travel.
- Hepatitis A
- Hepatitis B
- Poliovirus (the inactivated vaccine)
- Influenza, if it wasn’t given in the first round
The Peanut Butter Shot
The injection recruits dread most isn’t a vaccine at all. The bicillin shot, universally called the “peanut butter shot,” is a dose of benzathine penicillin G, a long-acting antibiotic injected deep into the glute muscle. The military uses it to stop outbreaks of group A streptococcus, the bacteria behind strep throat, which spreads fast through training barracks packed with stressed, sleep-deprived recruits.3Defense Technical Information Center. Chemoprophylaxis Against Group A Streptococcus During Military Training
The nickname comes from the medication’s thick, paste-like consistency. Because the antibiotic is so viscous, the injection site stays sore far longer than a normal shot. Many recruits describe a deep ache in the buttock that makes sitting down uncomfortable for a day or two. The best advice: keep moving afterward and massage the area to help the medication disperse. Sitting still and babying it makes the soreness worse.
If you’re allergic to penicillin, get that allergy documented in your medical records before you ship. Penicillin-allergic recruits are given an alternative or exempted from the injection entirely.
How the Shot Line Actually Works
The pneumatic jet injectors that left matching circular scars on a generation of veterans were phased out years ago over cross-contamination concerns. Today’s shot line uses standard disposable needles and syringes.
The process is still efficient. You roll up both sleeves and move through a corridor of stations, each staffed by a corpsman, medic, or nurse. One station handles your left arm, the next your right, and you don’t stop walking. The whole sequence takes minutes, and the speed is intentional. Less time to tense up means fewer problems. Some recruits get more stations than others depending on existing immunity, so the person behind you might finish before you do.
Side Effects to Expect
Getting half a dozen injections in one sitting produces predictable discomfort. Soreness at the injection sites is universal, and your arms will feel heavy and stiff for a day or two if you received several shots in the same arm. Low-grade fever, fatigue, and muscle aches are common and usually clear within 48 hours. None of it gets you out of training. Drill instructors have seen every reaction, and mild soreness won’t earn you a day off.
If mild symptoms last longer than seven days or get worse rather than better, report to sick call. For anything that feels like a genuine emergency, such as chest pain, difficulty breathing, or severe swelling, go to the nearest medical facility immediately.4Health.mil. Vaccine Safety and Adverse Events
Bring Your Vaccination Records
The single most useful thing you can do before shipping out is bring every vaccination record you can find. Childhood shot records, school immunization forms, a printout from your state immunization registry — the more documentation you have, the fewer needles you face.
Medical staff review your records against the required list and can skip any vaccine for which you already have documented immunity. The joint service regulation directs personnel to conduct blood titer testing where available, at a minimum for measles, rubella, hepatitis A, hepatitis B, and varicella. A titer test measures your antibody levels through a blood draw, and if results show adequate immunity, you skip that vaccine. A positive titer can also serve as the basis for a formal exemption.5Headquarters RIO. Labs and Immunizations
Show up with no records and no way to prove prior immunity, and you should expect the full battery. The military’s default is to vaccinate rather than assume you’re protected.
Vaccines You Won’t Get in Basic Training
Some shots people ask about don’t come during initial training at all. COVID-19 is one. The Department of Defense rescinded its COVID-19 vaccination mandate in January 2023, and the vaccine is no longer required for recruits.6U.S. Department of Defense. DOD Rescinds COVID-19 Vaccination Mandate
Deployment vaccines are another. These are tailored to the threat environment of a specific region and are given later, once you have orders. They include:
- Anthrax, reserved for personnel deploying to designated high-threat areas
- Smallpox, kept available for specific biodefense assignments
- Typhoid, before deployment to endemic regions
- Yellow fever, before travel to or transit through endemic areas
- Japanese encephalitis, for certain assignments in the Pacific
One branch exception matters here. The Marine Corps requires yellow fever vaccination for all accessions, regardless of deployment orders. The other branches administer it only when a specific assignment calls for it.7U.S. Navy Medicine. Immunizations and Chemoprophylaxis for the Prevention of Infectious Diseases
If You Want To Skip a Shot
Exemptions exist but they’re narrow, and getting one as a brand-new recruit is harder than most people expect.
Medical exemptions cover situations where a specific vaccine poses a genuine health risk. A documented penicillin allergy exempts you from the bicillin shot. A history of anaphylactic reaction to a vaccine or one of its components is grounds for exemption from that particular vaccine. Pregnancy also qualifies. All medical exemptions require documentation from a licensed healthcare provider.5Headquarters RIO. Labs and Immunizations
Administrative exemptions are non-medical command decisions entered into the Medical Readiness Reporting System. They’re less common for recruits in initial training and more typical for reservists or personnel in unusual duty circumstances.8United States Marine Corps. 2025-2026 Influenza Vaccine Guidance for Active and Reserve Components
Religious accommodation requests exist in DoD policy, but the approval process involves multiple levels of review, and the military’s obligation to maintain unit health weighs heavily against granting them. For recruits who haven’t completed training yet, these requests are rarely successful.
Mandatory vaccinations are lawful orders, and refusing one falls under Article 92 of the Uniform Code of Military Justice. If you have a legitimate medical reason to skip a specific shot, the exemption process works. If you just don’t want the shots, basic training will be a very short experience.