La vacunación y la desparasitación están confirmadas.

Spanish often repeats the article when two nouns are joined by y, especially when they are being treated as two separate items.

So La vacunación y la desparasitación sounds very natural and clear:

• the vaccination
• and the deworming / parasite treatment

You may sometimes see a shared article with coordinated nouns, but here repeating la is standard and natural.

Vacunación means vaccination or the act/process of vaccinating.

It is different from vacuna, which means vaccine. For example:

• La vacuna = the vaccine
• La vacunación = the vaccination

So this sentence is talking about the procedure/status of vaccination, not the vaccine itself.

Desparasitación means deworming or more generally parasite treatment.

It comes from parásito (parasite) and the verb desparasitar (to deworm / to remove parasites from).

In Spain, this word is very common in veterinary or pet-related contexts. Depending on the situation, it may refer to:

• internal parasite treatment
• external parasite treatment
• or parasite treatment in general

Because the subject is plural.

The subject is La vacunación y la desparasitación — two things joined by y. In Spanish, that makes a plural subject, so the verb must also be plural:

• está = is
• están = are

So:

• La vacunación está confirmada. = The vaccination is confirmed.
• La vacunación y la desparasitación están confirmadas. = The vaccination and deworming are confirmed.

Confirmadas agrees with the two nouns it refers to.

Both nouns are:

• feminine: la vacunación, la desparasitación
• together they are plural because there are two items

So the adjective/past participle must also be feminine plural:

• confirmado = masculine singular
• confirmada = feminine singular
• confirmados = masculine plural / mixed plural
• confirmadas = feminine plural

That is why the sentence ends with confirmadas.

Here, estar is used because the sentence describes a state or status: the vaccination and deworming are in the state of being confirmed.

• estar confirmado/a = to be confirmed
• ser confirmado/a would usually sound different and is not the normal choice here

In this sentence, están confirmadas means something like have been confirmed / are confirmed as a current status.

In this sentence, it functions like an adjective.

Although confirmadas comes from the past participle of confirmar (to confirm), in están confirmadas it describes the current state of the two nouns.

So you can think of the structure as:

• estar + past participle used adjectivally

This is very common in Spanish:

• La puerta está cerrada. = The door is closed.
• Los documentos están firmados. = The documents are signed.
• La vacunación y la desparasitación están confirmadas. = The vaccination and deworming are confirmed.

You may hear article omission in some coordinated phrases, but in this sentence La vacunación y la desparasitación is the clearest and most natural standard wording.

Keeping both articles helps show that these are two distinct procedures. In formal or administrative language, repeating the article is especially common.

So for a learner, use both articles.

Both words end in -ción, and the stress falls on the last syllable:

• va-cu-na-CIÓN
• des-pa-ra-si-ta-CIÓN

In Spanish spelling, words ending in n, s, or a vowel are normally stressed on the second-to-last syllable unless there is a written accent. The accent mark shows that the stress is on the final syllable instead.

So the accents are required:

• vacunación
• desparasitación

A rough pronunciation in Peninsular Spanish would be:

la ba-ku-na-THYON ee la dehs-pa-ra-see-ta-THYON es-TAN kom-feer-MA-das

A few useful notes for Spain:

• v in vacunación sounds very similar to b
• c before i or e is usually pronounced like th in much of Spain:
  vacunación, desparasitación
• y is pronounced like ee when it means and
• stress falls on:
  • vacunación
  • desparasitación
  • confirmadas

Not exactly; the meaning changes.

• Las vacunas = the vaccines
• La vacunación = the vaccination process/status

So:

• Las vacunas están confirmadas would mean the vaccines are confirmed, which is usually not what you want.
• La vacunación está confirmada means the vaccination has been confirmed as done/recorded/verified.

In administrative, medical, or veterinary contexts, vacunación is the better choice when talking about records or status.

It sounds like a formal or semi-formal statement, especially in:

• veterinary records
• pet adoption documents
• medical or care records
• administrative checklists

It suggests that both procedures have been verified, recorded, or approved.

Because of desparasitación, the most likely context is something related to animals, especially pets.