A elisa at a 3 month or a 13 week period is almost accurate. However its difficult to explain the word "almost" in medical terms, as there could be rare cases which would have ruled out that "almost". So being on a positive side, a elisa on a 3 month period is conclusive. If necessary the test can be repeated after 6 months, based on a doctors advice. Self diagonostics is not necessary.
A pcr dna test differs from a elisa in a way that the elisa looks for the antibodies in the blood, which a pcr dna looks for the actual viral load count. However, for a first diagonostics, a pcr dna is not recommended due to the fact that it is highly expensive compared to a simple elisa.
When elisa can proove, why a pcr dna. Thats why its just used as a confirmatory test after repeative elisa turning positive
